brass rod which is placed at the bottom of the burner. On turning the cock so as to open it, a small flow of gas occurs opposite the platinum spiral, while at the same time a rigid projecting piece affixed to the cock bears against a small, vertical metallic piece, and brings it in contact with the brass rod. The circuit is thus closed for an instant, the spiral is raised to a red heat, and lights the gas, and the flame rises and finally lights the burner. It goes without saying that on continuing the motion the contact is broken, so as not uselessly to waste the pile and so as to stop the escape of gas.
For gas furnaces, Mr. Loiseau is constructing a _handle-lighter_ which is connected with the side of the furnace by flexible cords. The contact button is on the sleeve itself, and the spiral is protected against shocks by a metallic covering which is cleft at the extremity and the points bent over at a right angle. All the lighters here described work well, and are rendering valuable services. They may be considered as the natural and indispensable auxiliaries of electric call bells, and their use has most certainly been rendered practical through the Leclanche pile.
* * * * *
THEILER’S TELEPHONE RECEIVER.
This telephone receiver differs from its predecessors in dispensing with an armature, the lateral vibration of the electro-magnet itself being utilized. In previous systems in which an electro-magnet is used, the sonorous vibrations are due either to the motion of an iron diaphragm or armature placed close to the poles of the electro-magnet, or to the expansion and contraction of the magnet itself. In Theiler’s telephone the electro-magnet may be of the usual U-shape, and may consist either of soft iron or of hardened steel permanently magnetized, wound with a suitable number of turns of insulated wire. This electro magnet is fixed in such a manner that the vibration of either one or of both its limbs is communicated to a diaphragm or diaphragms The patentees also employ two or more electro-magnets in the same circuit, and utilize the vibration of both magnets in the manner described. By attaching a light disk or disks to the vibrating limbs, the diaphragm may be dispensed with. Fig. 1 represents one of the telephone receivers provided with two diaphragms or sounding boards, connected to the two limbs or cores of the U-shaped electro-magnet by short tongues. These tongues are firmly inserted in the diaphragms and fixed to the magnet, as shown. The poles of the electro-magnet are brought very close together by being shaped as shown, and the middle part of the magnet is firmly screwed to the case of the instrument. The ends of the helix surrounding the magnet cores may be attached as usual to two terminals, or soldered to a flexible conductor communicating with the other parts of the telephone apparatus. When a vibratory current is sent through the helix of the electro-magnet, the extremities are rapidly attracted and repelled, and this vibratory motion of the magnet cores being communicated to the diaphragms or sounding boards, the latter are set in vibration of varying amplitude produced by a current of varying strength, as in all other telephones. Instead of making the electro-magnet of one continuous piece of iron, as represented in Fig. 1, the patentees find it more practicable to make it of the form shown in Fig. 2, where the electro-magnet represented consists of two limbs or cores, a sole piece, and pole extensions, the whole being screwed together, and practically constituting one continuous piece of iron carrying the two coils. In Fig. 2 only one of the limbs or cores of the electro-magnet is attached to the diaphragm, the other limb being held fixed by a screw. Sometimes the patentees hinge one of the magnet cores, or both, in the sole piece, in which case the diaphragms or sounding boards can be made much thicker than when the cores are rigidly fixed to the sole piece, because the magnetic attraction of the poles has then only to overcome the resistance of the diaphragm. Instead of using a diaphragm, they sometimes fix a stem to one of the cores of the electro-magnet, and mount thereon a light disk of vulcanite, wood, ivory, gutta-percha, or any other substance which it is capable of vibrating. When using this telephone receiver, the disk is pressed to the ear in such a manner that its surface covers the aperture of the ear. When these telephone receivers are used on a line of some considerable length, the patentees prefer to magnetize the electro-magnet by a constant current from a local battery, and to effect the variation of this constant magnetization inductively and not directly. The electro-magnet is, then, not inserted in the line at all, but in the primary circuit of an induction coil, and connected with a local battery. The line is connected to the secondry circuit of the induction coil. This device possesses the advantage that the electro-magnet can be powerfully magnetized with very little battery power, no matter how long the line may be, and that steel magnets are entirely dispensed with. It is not necessary to have a separate battery for this purpose, as the microphone battery may also be used for the telephone receiver. The shape of the vibrating electro-magnets is immaterial, as they may be made of a variety of forms.–_Eng. Mechanic_.
[Illustration: FIG. 1. FIG. 2]
* * * * *
ON AN ELECTRIC POWER HAMMER.
By MARCEL DEPREZ.
[Footnote: _La Lumiere Electrique_.]
In a lecture delivered by me on the 15th of last June in the amphitheater of the Conservatoire des Arts et Metiers, on the application of electricity to the production, transmission, and division of power, I operated for the first time an electric power hammer that I shall here describe. Its essential part is a sectional solenoid that I have likewise made an application of in an electric motor which I presented in July, 1830, to the Societe de Physique. Let us suppose we superpose, one on the other, a hundred flat bobbins of a centimeter in thickness in such a way as to form a single solenoid one meter in height, and that the incoming and outgoing wires of each of them be connected with the contiguous bobbins exactly in the same way as they are in the consecutive sections or a dynamo-electric machine ring. Finally, let us complete the resemblance by causing each junction of the wire of one of the bobbins with the wire of its neighbor to end in a metallic plate set into an insulating piece containing as many plates as there are bobbins, plus one. Over this species of collector, which maybe rectilinear or wound around a cylinder, let us pass two brushes fixed to an insulating piece that may be moved by hand. Now, if we place these two brushes at a distance such that the number of the plates of the collector included between them be, for example, equal to ten, and we give them any degree of displacement whatever, after rendering them interdependent, the current entering through one of these brushes and making its exit through the other will always traverse 10 bobbins. Everything will occur, then, as if we caused the ten-bobbin solenoid to move instead of the brushes. This granted, and the brushes being in any position whatever, let us send a current into the apparatus, and place therein a soft iron cylinder. By virtue of a well known law, such cylinder will remain suspended in the interior of the solenoid, and its longitudinal center will place itself at so much the greater distance from that of the solenoid the more the current increases in intensity. It would even fall entirely if the current had not an intensity above a minimum value dependent upon many elements concerning which we have not now to occupy ourselves. We will suppose the current intense enough to keep the distance of the two centers much below that which would bring about a fall of the cylinder. When such a condition is fulfilled, it is found that if we try to remove the iron cylinder from the equilibrium that it is in, we must apply a pressure that increases with the amount of separation, just exactly as if it were suspended from a spring. It results from this fact that if we displace the brushes a distance equal to the thickness of one plate of the collector, the active solenoid will undergo the same displacement, and its longitudinal center will move away from that of the iron cylinder, and that the attraction exerted upon the latter will increase. It will not be able to assume its first value, and equilibrium cannot be re-established unless the cylinder undergoes a displacement identical with that of the solenoid. Now, as this latter depends upon the motion communicated to the system of brushes, we see that, definitively, the cylinder will faithfully reproduce the motion communicated to the brushes by the hand of the operator. This apparatus, then, constitutes a genuine electric servo-motor in which the current is never interrupted nor modified in quantity or direction, no more indeed than the magnetization developed in the soft iron cylinder. Everything takes place as if the iron cylinder were suspended in a solenoid ten centimeters in length that was caused to rise and fall; with the difference that the weight of the cylinder exerts no action on the hand of the operator.
[Illustration: ELECTRIC POWER HAMMER.]
These explanations being understood, there remain but few things to be said to cause the operation of the hammer to be thoroughly comprehended. The elementary sections constituting the electric cylinder, A B, of the hammer are 80 in number, and form a total length of one meter. Their ingoing and outcoming wires end in a collector of circular form shown at F G. The brushes are replaced by two strips, C E and C D, fixed to the double winch, H C I, which is movable around the fixed center, C. They can make any angle whatever with each other, so that by trial there maybe given the active solenoid the most suitable length. When such angle has been determined, the angle, E C D, is rendered invariable by means of a set screw, and the apparatus is maneuvered by imparting to the double winch, H C I, an alternating circular motion.
The iron cylinder weighs 23 kilogrammes; but, when the current has an intensity of 43 amperes and traverses 15 sections, the stress developed may reach 70 kilogrammes; that is to say, three times the weight of the hammer. So this latter obeys with absolute docility the motions of the operator’s hands, as those who were present at the lecture were enabled to see.
I will incidentally add that this power hammer was placed on a circuit derived from one that served likewise to supply three Hefner-Alteneck machines (Siemens D{5} model) and a Gramme machine (Breguet model P.L.). Each of these machines was making 1,500 revolutions per minute and developing 25 kilogrammeters per second, measured by means of a Carpentier brake. All these apparatus were operating with absolute independence, and had for generator the double excitation machine that figured at the Exhibition of Electricity.
In an experiment made since then, I have succeeded in developing in each of these four machines 50 kilogrammeters per second, whatever was the number of those that were running; and I found it possible to add the hammer on a derived circuit without notably affecting the operation of the receivers.
It results from this that with my system of double excitation machine I have been enabled to easily run with absolute independence six machines, each giving a two-third horse-power. The economic performance, e/E, moreover, slightly exceeded 0.50.
* * * * *
SOLIGNAC’S NEW ELECTRIC LAMP.
When it becomes a question of practical lighting, it is very certain that the best electric lamp will be the one that is most simple and requires the fewest mechanical parts. It is to such simplicity that is due all the success of the Jablochkoff candle and the Reynier-Werdermann lamp. Yet, in the former of these lamps, it is to be regretted that the somewhat great and variable resistance opposed to the current in its passage through two carbons that keep diminishing in length, in measure as they burn, proves a cause of loss of light and of variation in it. And it is also to be regretted that the duration of combustion of the carbons is not longer; and, finally, it is allowable to believe that the power employed in volatilizing the insulator placed between the carbons is prejudicial to the economical use of this system. In order to obviate this latter inconvenience, an endeavor has been made in the Wilde candle to do away with the insulator, but the results obtained have scarcely been encouraging. An endeavor has also been made to render the duration of the carbons greater by employing quite long ones, and causing these to move forward successively through the intermedium of a species of rollers, or of counterpoises, as in the lamps of Mersanne and Werdermann; but then the system becomes more complicated. Finally, in order to keep the resistance of the carbons at a minimum and constant, their contact with the rheophores of the circuit has been established at a short distance from the arc, and this is one of the principal advantages possessed by the Reynier-Werdermann system. At a certain epoch it was thought that the problem might be simply solved by arranging in front of each other two carbons actuated by a spiral spring, as in car lamps, and kept at a proper distance apart for forming the electric arc by two funnel-shaped pieces of calcined magnesia, into which they entered like a wedge in measure as their conical point were away through combustion. This was the system of Mr. De Baillehache, and the trials that were made therewith were very satisfactory. But, unfortunately, the magnesia was not able to resist very long the temperature to which it was submitted. The problem found a better solution in the sun-lamp but has been solved in another manner, and just as simply, by Mr. Solignac, and the results obtained by him have been very satisfactory as regarded from the standpoint of steadiness of the luminous point.
In this system, a general view of which is given in Fig. 1, and the arrangement in Figs. 2 and 3, the carbons, F F, which are horizontal and about fifty centimeters in length, are thrust toward each other by two barrels, K, K, which wind up two chains, E, E, passing around the pulleys, D, D, fitted to the extremities of the carbons. These latter are provided beneath with small glass rods, G, G, whose extremities toward the arc abut at a short distance from the latter against a nickel stop, L (Fig. 3), which supports them, moreover, at M, by means of a tappet whose position is regulated by a screw. The current is transmitted to the carbons by two friction rollers, I, I, which serve at the same time as a guide for them, and which give the electric flux a passage of only one or two centimeters over the front of the carbon to form the arc. Finally, the whole is held by a support, A, and two pieces, CB, CB, which at the same time lead the current to the friction rollers through projections, J. The two systems are made to approach or recede from each other, in order to form the arc, by means of a regulating screw, H.
At present, the lighting of these lamps is effected by means of this screw, H, but Mr. Solignac is now constructing a model in which the lighting will be performed automatically by means of a solenoid that will react upon a carbon lighter, as in several already well known systems.
[Illustration: Fig. 1]
If the preceding description has been well-understood, it will be seen that the carbons are arrested in their movement toward each other only by the glass rods, G, abutting against L; but, as the stops, L, are not far from the arc, and as the heat to which they are exposed is so much the greater in proportion as the incandescent part of the carbons is nearer them, it results that for a certain elongation of the arc the temperature becomes sufficient to soften the glass of the rods, G, G, so that they bend as shown at O (Fig. 3), and allow the carbons to move onward until the heat has sufficiently diminished to prevent any further softening of the glass. In measure as the wearing away progresses, the preceding effects are reproduced; and, as these are produced in an imperceptible and continuous manner, there is perceived no jumping nor inconstancy in the light of the arc. Under such conditions, then, the regulation of the arc is effected under the very influence of the effect produced; and not under that of an action of a different nature (electro-magnetism), as happens in other regulators. It is certain that this idea is new and original, and the results that we have witnessed from it have been very satisfactory. There is but one regulation to perform, and that at the beginning, but this once done the apparatus operates with certainty, and for a long time. With a Meritens machine of the first model it has been found possible to light five lamps of this kind placed in the same circuit.
[Illustration: Fig. 2]
According to the inventor, this lamp will give a light of 100 carcels per one horse-power, and with a three horse-power six lamps may be lighted; but we have made no experiments to ascertain the correctness of these figures.
As for the cost of the glass rods, that amounts to one franc per two hundred meters length. They can, then, be considered only as an insignificant expense in the cost of the carbons. We consequently believe that it will be possible to employ this system advantageously in practice.–_Th. du Moncel_.
[Illustration: Fig. 3]
* * * * *
MONDOS’S ELECTRIC LAMP.
Since the month of May last, the concert at the Champs Elysees has been lighted by sixteen voltaic arc lamps on a new and very simple system, which gives excellent results in the installation under consideration. The sixteen lamps are on the divisible system, and their regulation is based upon the principle of derivation. They are supplied by a Siemens alternating current machine and arranged in four circuits, on each of which are mounted four lamps in series. The accompanying figures will allow the reader to readily understand the system, which is as simple as it is ingenious, and which has been combined by Mr. Mondos so as to obtain a continuous and independent regulation of each lamp.
In this system the lower carbon is stationary, the luminous point descending in measure as the carbons wear away through combustion. The upper carbon descends by its own weight, and imperceptibly, so as to keep the arc at its normal length.
The mechanism that controls the motions of the upper rod that supports the carbon-holder consists of two bobbins of fine wire, E (Fig. 2), mounted on a derived circuit on the terminals of the lamp; of a lever, L, articulated at O, and supporting a tube, TT’, and the whole movable part balanced by a counterpoise, P. This lever, P, carries two soft iron cores, F, which enter the bobbins, E, and become magnetized under the influence of the current that passes through them. The upper part of the tube, T, carries a square upon which is articulated at O’ a second lever, L’, balanced by a second counterpoise, P’, and carrying a flat armature, _p_, opposite the cores, F’, that are fixed to the first horizontal lever, L. The carbon-holder rod, CC’, slides freely in the tube, TT’, and is wedged therein by a small piece, _a m l_, fixed to the lever, L’. For this reason the tube, TT’, is provided with a notch opposite the piece _a m l_, and the two arms, _a_ and _m_, of the latter are shaped like a V, as may be seen in part in the plan in Fig. 2. It is now easy to understand how the system operates; when the current is not traversing the circuit, the carbons are separated; but, at the moment the circuit is closed for lighting a series of lamps, it traverses the electro-magnet, which then becomes very powerful, and draws down the cores, F, along with the lever, L, the tube, TT’, and the carbon-holder, CC’, and brings the carbons in contact. The arc then forms, and the current divides between the arc and the bobbins, E. Its action upon the cores, F, becomes weak, and it can no longer balance the counterpoise, P, which falls back, and raises the system again. The arc thus becomes _primed_. The cores, F, however, preserve a certain amount of magnetization; the armature, _p_, is attracted, and the lever, L’, assumes a position of equilibrium such that the piece, _a m l_, wedges the rod, CC’, in the tube, TT’, and holds it suspended. When, through wear of the carbons, the arc elongates, a greater portion of the current passes into the bobbins, E, the armature, _p_, is attracted with more force, and the lever, L’, swings around the point, O’. The rotation of L’ separates the piece, _a m l_, from the rod, CC’, which, being thus set free, slides by its own weight and shortens the arc. The current then becomes weak in E, the armature, _p_, is not so strongly attracted, the lever, L’, pivots slightly around O’ under the action of the weight, P’, and the brake or wedge enters the notch anew, and stops the descent of the carbon. In practice, the motions that we have just described are exceedingly slight; the carbon moves imperceptibly, and the length of the arc remains invariable.
[Illustration: Fig. 1–MONDOS’S ELECTRIC LAMP.]
It will be seen, then, that the lever, L, and the tube, TT’, serve exclusively for _lighting_, and the lever, L’, exclusively for regulating the distance of the carbons.
This lamp exhibits great elasticity, and can operate, without a change of any part of its mechanism, with currents of very different intensities. It suffices for obtaining a proper working of the apparatus in each case, to regulate the distance from the weight, P’, to the point of suspension, O’, and the distance from the armature, _p_, to the cores, F. At the Champs Elysees concerts the lamps are operating with alternating currents; but they are capable of operating with continuous ones also, although the slight tremor of the electro-magnetic system, due to the use of alternating currents and as a consequence of rapid changes of magnetization, seems in principle very favorable to systems in which the descent of the carbon is based upon friction instead of a clutch. At the Champs Elysees concerts the lamps burn crayons of 9 to 10 millimeters with a current of 9 to 10 amperes and an effective electro-motive power of 60 volts per lamp. The light is very steady, and the effect produced is most satisfactory. The dispensing with all clock-work movement and regulating springs makes this electric lamp of Mr. Mondos a simple and plain apparatus, capable of numerous applications in the industries, in wide, open spaces, in all cases where foci of medium intensity have to be employed, and where it is desired to arrange several lamps in the same circuit.–_La Nature_.
[Illustration: Fig. 2–REGULATING MECHANISM.]
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[AMERICAN POTTERY AND GLASSWARE REPORTER.]
ALUMINUM–ITS PROPERTIES, COST, AND USES.
Aluminum is a shining, white, sonorous metal, having a shade between silver and platinum. It is a very light metal, being lighter than glass and only about one-fourth as heavy as silver of the same bulk. It is very malleable and ductile, and is remarkable for its resistance to oxidation, being unaffected by moist or dry air, or by hot or cold water. Sulphureted hydrogen gas, which so readily tarnishes silver, forming a black film on the surface, has no action on this metal.
Next to silica, the oxide of aluminum (alumina) forms, in combination, the most abundant constituent of the crust of the earth (hydrated silicate of alumina, clay).
Common alum is sulphate of alumina combined with another sulphate, as potash, soda, etc. It is much used as a mordant in dyeing and calico printing, also in tanning.
Aluminum is of great value in mechanical dentistry, as, in addition to its lightness and strength, it is not affected by the presence of sulphur in the food–as by eggs, for instance.
Dr. Fowler, of Yarmouthport, Mass., obtained patents for its combination with vulcanite as applied to dentistry and other uses. It resists sulphur in the process of vulcanization in a manner which renders it an efficient and economical substitute for platinum or gold.
Aluminum is derived from the oxide alumina, which is the principal constituent of common clay. Lavoissier, a celebrated French chemist, first suggested the existence of the metallic bases of the earths and alkalies, which fact was demonstrated twenty years thereafter by Sir Humphry Davy, by eliminating potassium and sodium from their combinations; and afterward by the discovery of the metallic bases of baryta, strontium, and lime. The earth alumina resisting the action of the voltaic pile and the other agents then used to induce decomposition, twenty years more passed before the chloride was obtained by Oerstadt, by subjecting alumina to the action of potassium in a crucible heated over a spirit lamp. The discovery of aluminum was at last made by Wohler in 1827, who succeeded in 1846 in obtaining minute globules or beads of this metal by heating a mixture of chloride of alumina and sodium. Deville afterward conducted some experiments in obtaining this metal at the expense of Napoleon III., who subscribed L1,500, and was rewarded by the presentation of two bars of aluminum. The process of manufacture was afterward so simplified that in 1857 its price at Paris was about two dollars an ounce. It was at first manufactured from common clay, which contains about one-fourth its weight of aluminum, but in 1855 Rose announced to the scientific world that it could be obtained from a material called “cryolite,” found in Greenland in large quantities, imported into Germany under the name of “mineral soda,” and used as a washing soda and in the manufacture of soap. It consists of a double fluoride of aluminum, and only requires to be mixed with an excess of sodium and heated, when the mineral aluminum at once separates. Its cost of manufacture is given in this estimate for one pound of metal: 16 lb. of cryolite at 8 cents per pound, $1.28: 21/2 lb. metallic sodium at about 26 cents per pound, 70 cents; flux and cost of reduction, $2.02; total, $4.
Aluminum is used largely in the manufacture of cheap jewelry by making a hard, gold-colored alloy with copper, called aluminum bronze, consisting of 90 per cent. of copper and 10 per cent. of aluminum. Like iron, it does not amalgamate directly with mercury, nor is it readily alloyed with lead, but many alloys with other metals, as copper, iron, gold, etc., have been made with it and found to be valuable combinations. One part of it to 100 parts of gold gives a hard, malleable alloy of a greenish gold color, and an alloy of 3/4 iron and 1/4 aluminum does not oxidize when exposed to a moist atmosphere. It has also been used to form a metallic coating upon other metals, as copper, brass, and German silver, by the electro-galvanic process. Copper has also been deposited, by the same process, upon aluminum plates to facilitate their being rolled very thin; for unless the metal be pure, it requires to be annealed at each passage through the rolls, and it is found that its flexibility is greatly increased by rolling. To avoid the bluish white appearance, like zinc, Dr. Stevenson McAdam recommends immersing the article made from aluminum in a heated solution of potash, which will give a beautiful white frosted appearance, like that of frosted silver.
F.W. Gerhard obtained a patent in 1856, in England, for an improved means of obtaining aluminum metal, and the adaptation thereof to the manufacture of certain useful articles. Powdered fluoride of aluminum is placed alone or in combination with other fluorides in a closed furnace, heated to a red heat, and exposed to the action of hydrogen gas, which is used as a reagent in the place of sodium. A reverberating furnace is used by preference. The fluoride of aluminum is placed in shallow trays or dishes, each dish being surrounded by clean iron filings placed in suitable receptacles; dry hydrogen gas is forced in, and suitable entry and exit pipes and stop-cocks are provided. The hydrogen gas, combining with the fluoride, “forms hydrofluoric acid, which is taken up by the iron and is thereby converted into fluoride of iron.” The resulting aluminum “remains in a metallic state in the bottom of the trays containing the fluoride,” and may be used for a variety of manufacturing and ornamental purposes.
The most important alloy of aluminum is composed of aluminum 10, copper 90. It possesses a pale gold color, a hardness surpassing that of bronze, and is susceptible of taking a fine polish. This alloy has found a ready market, and, if less costly, would replace red and yellow brass. Its hardness and tenacity render it peculiarly adapted for journals and bearings. Its tensile strength is 100,000 lb., and when drawn into wire, 128,000 lb., and its elasticity is one-half that of wrought iron.
General Morin believes this alloy to be a perfect chemical combination, as it exhibits, unlike the gun metal, a most complete homogeneousness, its preparation being also attended by a great development of heat, not seen in the manufacture of most other alloys. The specific gravity of this alloy is 7.7. It is malleable and ductile, may be forged cold as well as hot, but is not susceptible of rolling; it may, however, be drawn into tubes. It is extremely tough and fibrous.
Aluminum bronze, when exposed to the air, tarnishes less quickly than either silver, brass, or common bronze, and less, of course, than iron or steel. The contact of fatty matters or the juice of fruits does not result in the production of any soluble metallic salt, an immunity which highly recommends it for various articles for table use.
The uses to which aluminum bronze is applicable are various. Spoons, forks, knives, candle-sticks, locks, knobs, door-handles, window fastenings, harness trimmings, and pistols are made from it; also objects of art, such as busts, statuettes, vases, and groups. In France, aluminum bronze is used for the eagles or military standards, for armor, for the works of watches, as also watch chains and ornaments. For certain parts, such as journals of engines, lathe-head boxes, pinions, and running gear, it has proved itself superior to all other metals.
Hulot, director of the Imperial postage stamp manufactory in Paris, uses it in the construction of a punching machine. It is well known that the best edges of tempered steel become very generally blunted by paper. This is even more the case when the paper is coated with a solution of gum arabic and then dried, as in the instance of postage stamp sheets. The sheets are punched by a machine the upper part of which moves vertically and is armed with 300 needles of tempered steel, sharpened in a right angle. At every blow of the machine they pass through the holes in the lower fixed piece, which correspond with the needles, and perforate five sheets at every blow. Hulot now substitutes this piece by aluminum bronze. Each machine makes daily 120,000 blows, or 180,000,000 perforations, and it has been found that a cushion of the aluminum alloy was unaffected after some months’ use, while one of brass is useless after one day.
Various formulae are given for the production of alloys of aluminum, but they are too numerous and intricate to enter into here.
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DETERMINATION OF POTASSA IN MANURES.
By M.E. DREYFUS.
The method generally adopted for the determination of potassa in manures, i. e., the direct incineration of the sample, may in certain cases occasion considerable errors in consequence of the volatilization of a portion of the potassium products.
To avoid this inconvenience, the author proposes a preliminary treatment of the manure with sulphuric acid at 1.845 sp. gr., to convert potassium nitrate and chloride into the fixed sulphate. The sulphuric acid attacks the manure energetically, and much facilitates the incineration, which may be effected at a dark red heat. The ignited portion (10 grms.) is exhausted with boiling distilled water acidulated with hydrochloric acid, and the filtrate, when cold, is made up to 500 c. c. Of this solution 50 c c., representing 1 grm. of the sample, are taken, and, after being heated until close upon ebullition, baryta-water is added until a strong alkaline reaction is obtained. The sulphuric and phosphoric acids, alumina, magnesia, etc, are thus precipitated. The filtrate is heated to a boil, and mixed with ammonia and ammonium carbonate, to precipitate the excess of baryta in solution. The last traces of lime are eliminated by means of a few drops of ammonium oxalate. The filtrate is evaporated down on the water-bath, and the ammoniacal salts are expelled by carefully raising the temperature to dull redness. After having taken up the residue in distilled water it is treated with platinum chloride, and the potassium chloro-platinate obtained is reduced with oxalic acid. The quantity of potassa present in the manure can be calculated from the weight of platinum obtained.–_Bull. de la Soc. Chim. de Paris_.
* * * * *
THE ORIGIN AND RELATIONS OF THE CARBON MINERALS.
[Footnote: Read before the New York Academy of Sciences, February 6, 1882.]
By J.S. NEWBERRY.
What are called the carbon minerals–peat, lignite, coal, graphite, asphalt, petroleum, etc.–are, properly speaking, not minerals at all, as they are organic substances, and have no definite chemical composition or crystalline forms. They are, in fact, chiefly the products or phases of a progressive and inevitable change in plant-tissue, which, like all organic matter, is an unstable compound and destined to decomposition.
In virtue of a mysterious and inscrutable force which resides in the microscopic embryo of the seed, a tree begins its growth. For a brief interval, this growth is maintained by the prepared food stored in the cotyledons, and this suffices to produce and to bring into functional activity–some root-fibrils below and leaves above, with which the independent and self-sustained life of the individual begins. Henceforward, perhaps for a thousand years, this life goes on, active in summer and dormant in winter, absorbing the sunlight as a motive power which it controls and guides. Its instruments are the discriminating cells at the extremities of the root-fibrils, which search for, select, and absorb the crude aliment adapted to the needs of the plant to which they belong, and the chlorophyl cells–the lungs and stomach of the tree–in the leaves. During all the years of the growth of the plant, these organs are mainly occupied in breaking the strongly riveted bonds that unite oxygen and carbon in carbonic acid; appropriating the carbon and driving off most of the oxygen. In the end, if the tree is, e. g., a _Sequoia_, some hundreds of tons of solid, organized tissue have been raised into a column hundreds of feet in height, in opposition to the force of gravitation and to the affinities of inorganic chemistry.
The time comes, however, sooner or later, when the power which has created and the life that has pervaded this wonderful structure abandon it. The affinities of inorganic chemistry immediately reassert themselves, in ordinary circumstances rapidly tearing down the ephemeral fabric.
The disintegration of organic tissue, when deserted by the force which has animated and preserved it, gives rise to the phenomena which form the theme of this paper.
Most animal-tissue decomposes with great rapidity, and plant tissue, when not protected, soon decays. This decay is essentially oxidation, since its final result is the restoration to the atmosphere of carbonic acid, which is broken up in plant-growth by the appropriation of its carbon. Hence it is a kind of combustion, although this term is more generally applied to very rapid oxidation, with the evolution of sensible light and heat. But, whether the process goes on rapidly or slowly, the same force is evolved that is absorbed in the growth of plant-tissue; and by accelerating and guiding its evolution, we are able to utilize this force in the production at will of heat, light, and their correlatives, chemical affinity, motive power, electricity, and magnetism. The decomposition of plants may, however, be more or less retarded, and it then takes the form of a destructive distillation, the constituents reacting upon each other, and forming temporary combinations, part of which are evolved, and part remain behind. Water is the great extinguisher of this as of the more rapid oxidation that we call combustion; and the decomposition of plant-tissue under water is extremely slow, from the partial exclusion of oxygen. Buried under thick and nearly impervious masses of clay, where the exclusion of oxygen is still more nearly complete, the decomposition is so far retarded that plant-tissue, which is destroyed by combustion almost instantaneously, and if exposed to “the elements”–moisture with a free access of oxygen–decays in a year or two, may be but partially consumed when millions of years have passed. The final result is, however, inevitable, and always the same, viz., the oxidation and escape of the organic mutter, and the concentration of the inorganic matter woven into its composition–in it, but not of it–forming what we call the ash of the plant.
Since the decomposition of organic matter commences the instant it is abandoned by the creative and conservative vital force, and proceeds uninterruptedly, whether slowly or rapidly, to the final result, it is evident that each moment in the progress of this decomposition presents us with a phase of structure and composition different from that which preceded and from that which follows it. Hence the succession of these phases forms a complete sliding scale, which is graphically shown in the following diagram, where the organic constituents of plant tissue–carbon, hydrogen, oxygen, and nitrogen–appear gradually diminishing to extinction, while the ash remains nearly constant, but relatively increasing, till it is the sole representative of the fabric.
[Illustration: DIAGRAM SHOWING THE GENETIC RELATIONS OF THE CARBON MINERALS.]
We may cut this triangle of residual products where we please, and by careful analysis determine accurately the chemical composition of a section at this point, and we may please ourselves with the illusion, as many chemists have done, that the definite proportions found represent the formula of a specific compound; but an adjacent section above or below would show a different composition, and so in the entire triangle we should find an infinite series of formulae, or rather no constant formulae at all. We should also find that the slice, taken at any point while lying in the laboratory or undergoing chemical treatment, would change in composition, and become a different substance.
In the same way we can snatch a brand from the fire at any stage of its decomposition, or analyze a decaying tree trunk during any month of its existence, and thus manufacture as many chemical formulae as we like, and give them specific names; but it is evident that this is child’s play, not science. The truth is, the slowly decomposing tissue of the plants of past ages has given us a series of phases which we have grouped under distinct names, and we have called one group peat, one lignite, another coal, another anthracite, and another graphite. We have spaced off the scale, and called all within certain lines by a common name; but this does not give us a common composition for all the material within these lines. Hence we see that any effort to define or describe coal, lignite, or anthracite accurately must be a failure, because neither has a fixed composition, neither is a distinct substance, but simply a conventional group of substances which form part of an infinite and indivisible series.
But this sliding scale of solid compounds, which we designate by the names given above, is not the only product of the natural and spontaneous distillation of plant tissue. Part of the original organic mass remains, though constantly wasting, to represent it; another part escapes, either completely oxidized as carbonic acid and water, or in a volatile or liquid form, still retaining its organic character, and destined to future oxidation, known as carbureted hydrogen, olefiant gas, petroleum, etc.
Hence, in the decomposition of vegetable tissue, two classes of resultant compounds are formed, one residual and the other evolved; and the genesis and relation of the carbon minerals may be accurately shown by the following diagram:
PLANT TISSUE
_________________
|
_Residual Products_ | _Evolved Products_ |
Peat. }
| }
Lignite. }
| } { Carbonic Acid.
Bitumious Coal. } { Carbonic Oxide. | } { Carbureted Hydrogen, etc. Semi-bitumious ” } { Water.
| } { {Maltha.
Anthracite. } { { |
| } { {Asphalt etc.
Graphitie Anthracite. } { Petro- { | | } { leum {Asphaltic Coal.
Graphite. } { |
| } {Asphaltic Anthracite. Ash. } { |
{ ” Graphite.
[NOTE.–In this diagram, the vertical line connecting the names of the residual products (and of the derivatives of petroleum) indicates that each succeeding one is produced by further alteration from that which precedes it, and not independently. Also, the arrangement of the braces is designed to show that any or all of the evolved products are given off at each stage of alteration.]
The theory here proposed has not been evolved from my inner consciousness, but has grown from careful study, through many years, of facts in the field. A brief sketch of the evidence in favor of it is all that we have space for here.
RESIDUAL PRODUCTS.
_Peat_.–Dry plant-tissue consists of about 50 per cent, of carbon, 44 per cent, of oxygen, with a little nitrogen, and 6 per cent. of hydrogen. In a peat-bog, we find the upper part of the scale represented above very well shown: plants are growing on the surface with the normal composition of cellulose. The first stratum of peat consists of browned and partially decomposed plant-tissue, which is found to have lost perhaps 20 per cent. of the components of wood, and to have acquired an increasing percentage of carbon. As we descend in the peat, it becomes more homogeneous and darker until at the bottom of the marsh ten or twenty feet from the surface, we have a black, carbonaceous paste, which, when dried, resembles some varieties of coal, and approaches them in composition. It has lost half the substance of the original plant, and shows a marked increase in the relative proportion of carbon.
_Lignite_.–Each inch in vertical thickness of the peat-bog represents a phase in the progressive change from wood-tissue to lignite, using this term with its common signification to indicate, not necessarily carbonized ligneous tissue, but plant-tissue that belongs to a past though modern geological age–i.e., Tertiary, Cretaceous, Jurassic, or Triassic. These lignites or modern coals are only peat beds which have been buried for a longer or shorter time under clay, sand, or solidified rock, and have progressed farther or less far on the road to coal. As with peats, so with lignites, we find that at different geological levels they exhibit different stages of this distillation–the Tertiary lignites being usually distinguished without difficulty by the presence of a larger quantity of combined water and oxygen, and a less quantity of carbon, than the Cretaceous coals, and these in turn differ in the same respects from the Triassic.
All the coals of the Tertiary and Mesozoic ages are grouped under one name; but it is evident that they are as different from each other as the new and spongy from the old and well-rotted peat in the peat-bog.
_Coal_.–By mere convention, we call the peat which accumulated in the Carboniferous age by the name of bituminous coal; and an examination of the Carboniferous strata in different countries has shown that the peat-beds formed in the Carboniferous age, though varying somewhat, like others, with the kind of vegetation from which they were derived, have a common character by which they may be distinguished from the more modern coals; containing less water, less oxygen, and more carbon, and usually exhibiting the property of coking, which is rare in coals of later date. Though there is great diversity in the Carboniferous coals, and it would be absurd to express their composition by a single formula, it may be said that, over the whole world, these coals have characteristics, as a group, by which they can be recognized, the result of the slow decomposition of the tissue of plants which lived in the Carboniferous age, and which have, by a broad and general change, approximated to a certain phase in the spontaneous distillation of plant-tissue. An experienced geologist will not fail to refer to their proper horizon a group of coals of Carboniferous age any more than those of the Cretaceous or Tertiary.
_Anthracite_–In the ages anterior to the Carboniferous, the quantity of land vegetation was apparently not sufficient to form thick and extensive beds of peat; but the remains of plant-tissue are contained in all the older formations, though there only as anthracite or graphite–the last two groups of residual products. Of these we have examples in the beds of graphite in the Laurentian rocks of Canada, and of anthracite of the lower Silurian strata of Upper Church and Kilnaleck, Ireland.
From these facts it is apparent that the carbon series is graded geologically, that is, by the lapse of time during which plant-tissue has been subjected to this natural and spontaneous distillation. But we have better evidence than this of the derivation of one from another of the groups of residual products which have been enumerated. In many localities, the coals and lignites of different ages have been exposed to local influences–such as the outbursts of trap-rock, or the metamorphism of mountain chains–which have hastened the distillation, and out of known earlier groups have produced the last. For example, trap outbursts have converted Tertiary lignites in Alaska into good bituminous coals; on Queen Charlotte’s Island, on Anthracite Creek, in southwestern Colorado, and at the Placer Mountains, near Santa Fe, New Mexico, Cretaceous lignites into anthracite; those from Queen Charlotte’s Island and southwestern Colorado are as bright, hard, and valuable as any from Pennsylvania. At a little distance from the focus of volcanic action, the Cretaceous coals of southwestern Colorado have been made bituminous and coking, while at the Placer Mountains the same stratum may be seen in its anthracitic and lignitic stages.
A still better series, illustrating the derivation of one form of carbon solids from another, is furnished by the coals of Ohio, Pennsylvania, and Rhode Island. These are of the same age; in Ohio, presenting the normal composition and physical characters of bituminous coals, that is, of plant tissue generally and uniformly descending the scale in the lapse of time from the Carboniferous age to the present. In the mountains of Pennsylvania the same coal beds, somewhat affected by the metamorphism which all the rocks of the Alleghanies have shared, have reached the stage of _semi-bituminous_ coals, where half the volatile constituents have been driven off; again, in the anthracite basins of eastern Pennsylvania, the distillation further effected has formed from these coals _anthracite_, containing only from three to ten per cent. of volatile matter; while in the focus of metamorphic action, at Newport, Rhode Island, the Carboniferous coals have been changed to _graphitic anthracite_, that is, are half anthracite and half graphite. Here, traveling from west to east, a progressive change is noted, similar to that which may be observed in making a vertical section of a peat bog, or in comparing the coals of Tertiary, Mesozoic, and Carboniferous age, only the latter is the continuation and natural sequence of the former series of changes.
In the Laurentian rocks of Canada are large accumulations of carbonaceous matter, all of which is graphite, and that which is universally conceded to be derived from plant-tissue. The oxidation of graphite is artificially difficult, and in nature’s laboratory slow; but it is inevitable, as we see in the decomposition of its outcrops and the blanching of exposed surfaces of clouded marbles, where the coloring is graphite. Thus the end is reached, and by observations in the field, the origin and relationship of the different carbon solids derived from organic tissue are demonstrated.
It only remains to be said, in regard to them, that all the changes enumerated may be imitated artificially, and that the stages of decomposition which we have designated by the names graphite, anthracite, coal, lignite, are not necessary results of the decomposition of plant-tissue. A fallen tree may slowly consume away, and all its carbonaceous matter may be oxidized and dissipated without exhibiting the phases of lignite, coal, etc.; and lignite and coal, when exposed to air and moisture, are burned away to ashes in the same manner, simply because in these cases complete oxidation of the carbon takes place, particle by particle, and the mass is not affected as a whole in such a way as to assume the intermediate stages referred to. Chemical analysis, however, proves that the process is essentially the same, although the physical results are different.
EVOLVED PRODUCTS.
The gradual wasting of plant-tissue in the formation of peat, lignite, coal, etc., may be estimated as averaging for peat, 20 to 30 per cent.; lignite, 30 to 50 per cent.; coal, 50 to 70 per cent.; anthracite, 70 to 80; and graphite, 90 per cent. of the original mass. The evolved products ultimately represent the entire organic portion of the wood–the mineral matter, or ash, being the only residuum. These evolved products include both liquids and gases, and by subsequent changes, solids are produced from some of them. Carbonic acid, carbonic oxide, nitrogenous and hydrocarbon gases, water, and petroleum, are mentioned above as the substances which escape from wood-tissue during its decomposition. That all these are eliminated in the decay of vegetable and animal structures is now generally conceded by chemists and geologists, although there is a wide difference of opinion as to the nature of the process.
It has been claimed that the evolved products enumerated above are the results of the primary decomposition of organic matter, and never of further changes in the residual products; i.e., that in the breaking-up of organic tissue, variable quantities of coal, anthracite, petroleum, marsh gas, etc., are formed, but that these are never derived, the one from the other. This opinion is, however, certainly erroneous, and the formation of any or all the evolved products may take place throughout the entire progress of the decomposition. Marsh gas and carbonic acid are seen escaping from the surface of pools where recent vegetable matter is submerged, and they are also eliminated in the further decomposition of peat, lignite, coal, and carbonaceous shale. Fire damp and choke-damp, common names for the gases mentioned above, are produced in large quantities in the mines where Tertiary or Cretaceous lignites, or Carboniferous coals or anthracites are mined. It has been said that these gases are simply locked up in the interstices of the carbonaceous matter and are liberated in its excavation; but all who have worked coal mines know that such accumulations are not sufficient to supply the enormous and continuous flow which comes from all parts of the mass penetrated. We have ample proof, moreover, that coal, when exposed to the air, undergoes a kind of distillation, in which the evolution of carbonic acid and hydrocarbon gases is a necessary and prominent feature.
The gas makers know that if their coal is permitted to lie for months or years after being mined, it suffers serious deterioration, yielding a less and less quantity of illuminating gas with the lapse of time. So coking coals are rendered dry, non-caking, and valueless for this purpose by long exposure.
Carbureted hydrogen, olefiant gas, etc., are constant associates of the petroleum of springs or wells, and this escape of gas and oil has been going on in some localities, without apparent diminution, for two or three thousand years. We can only account for the persistence of this flow by supposing that it is maintained by the gradual distillation of the carbonaceous masses with which such evolutions of gas or of liquid hydro-carbons are always connected. If it were true that carbureted hydrogen and petroleum are produced only from the primary decomposition of organic tissue, it would be inevitable that at least the elastic gases would have escaped long since.
Oil wells which have been nominally exhausted–that is, from which the accumulations of centuries in rock reservoirs have been pumped–and therefore have been abandoned, have in all cases been found to be slowly replenished by a current and constant secretion, apparently the product of an unceasing distillation.
In the valley of the Cumberland, about Burkesville, one of the oil regions of the country, the gases escaping from the equivalent of the Utica shale accumulate under the plates of impervious limestone above until masses of rock and earth, hundreds of tons in weight, are sometimes thrown out with great violence. Unless these gases had been produced by comparatively recent distillation, such explosions could not occur.
In opening a coal mine on a hillside, the first traces of the coal seam are found in a dark stain in the superficial clay; then a substance like rotten wood is reached, from which all the volatile constituents have escaped. These appear, however, later, and continue to increase as the mine is deepened, until under water or a heavy covering of rock the coal attains its normal physical and chemical characters. Here it is evident that the coal has undergone a long-continued distillation, which must have resulted in the constant production of carbonic acid and carbureted hydrogen.
A line of perennial oil and gas springs marks the outcrop of every great stratum of carbonaceous matter in the country. Of these, the most considerable and remarkable are the bituminous shales of the Silurian (Utica shale), of the Devonian (Hamilton and Huron shales), the Carboniferous, etc. Here the carbonaceous constituent (10 to 20 per cent.) is disseminated through a great proportion of inorganic material, clay and sand, and seems, both from the nature of the materials which furnished it–cellular plants and minute animal organisms–and its dissemination, to be specially prone to spontaneous distillation. The Utica shale is the lowest of these great sheets of carbonaceous matter, and that supplies the hydro-carbon gases and liquids which issue from the earth at Collingwood, Canada, and in the valley of the Cumberland. The next carbonaceous sheet is formed by the great bituminous shale beds of the upper Devonian, which underlie and supply the oil wells in western Pennsylvania. In some places the shale is several hundred feet in thickness, and contains more carbonaceous matter than all the overlying coal strata. The outcrop of this formation, from central New York to Tennessee, is conspicuously marked by gas springs, the flow from which is apparently unfailing.
Petroleum is scarcely less constant in its connection with these carbonaceous rocks than carbureted hydrogen, and it only escapes notice from the little space it occupies. The two substances are so closely allied that they must have a common origin, and they are, in fact, generated simultaneously in thousands of localities.
During the oil excitement of some years since, when the whole country was hunted over for “oil sign,” in many lagoons, from which bubbles of marsh-gas were constantly escaping, films of genuine petroleum were found on the surface; and as the underlying strata were barren of oil, this could only have been derived from the decaying vegetable tissue below. In the Bay of Marquette, two or three miles north of the town, where the shore is a peat bog underlain by Archaean rocks, I have seen bubbles of carbureted hydrogen rising in great numbers attended by drops of petroleum which spread as iridescent films on the surface.
The remarks which have been made in regard to the heterogeneous nature of the solid hydrocarbons apply with scarcely less force to the gaseous and liquid products of vegetable decomposition. The gases which escape from marshes contain carbonic acid, a number of hydrocarbon gases (or the materials out of which they may be composed in the process of analysis), and finally a larger or smaller volume of nitrogenous gas. It is possible that the elimination of these gases takes the form of fractional distillation, and definite compounds may be formed directly from the wood-tissue or its derivatives, and mingle as they escape. This is, however, not certain, for the gases, as we find them, are always mixtures and never pure. In the liquid evolved products, the petroleums, this is emphatically true, for we combine under this name fluids which vary greatly in both their physical and chemical characters; some are light and ethereal, others are thick and tarry; some are transparent, some opaque; some red, some brown, others green; some have an offensive and others an agreeable odor; some contain asphalt in large quantity, others paraffine, etc. Thus they form a heterogeneous assemblage of liquid hydrocarbons, of which naphtha and maltha may be said to form the extremes, and which have little in common, except their undefinable name. The causes of these differences are but imperfectly understood, but we know that they are in part dependent on the nature of the organic material that has furnished the petroleums, and in part upon influences affecting them after their formation. For example, the oil which saturates the Niagara limestone at Chicago, and–which is undoubtedly indigenous in this rock, and probably of animal origin, is black and thick; that from Enniskillen, Canada, is also black, has a vile odor, probably in virtue of sulphur compounds, and, we have reason to believe, is derived from animal matter. The oils of northwestern Pennsylvania are mostly brown, sometimes green by reflected light, and have a pungent and characteristic odor. These are undoubtedly derived from the Hamilton shales, which contain ten or twenty per cent, of carbonaceous matter, apparently produced from the decomposition of sea-weeds, since these are in places exceedingly abundant, and nearly all other fossils are absent.
The oils of Italy, though varying much in appearance, have usually an ethereal odor that is rather agreeable; they are of Tertiary age. The oils of Japan, differing much among themselves, have as, a common character an odor quite different from the Pennsylvania oils. So the petroleums of the Caspian, of India, California, etc., occurring at different geological horizons, exhibit a diversity of physical and chemical characters which may be fairly supposed to depend upon the material from which they have been distilled. The oils in the same region, however, are found to exhibit a series of differences which are plainly the result of causes operating upon them after their production. Near the surface, they are thicker and darker; below, and near the carbonaceous mass from which they have been generated, they are of lighter gravity and color. We find, in limited quantity, oils which are nearly white and may be used in lamps without refining–which have been refined, in fact, in Nature’s laboratory. Others, that are reddish yellow by transmitted light, sometimes green by reflected light, are called amber oils; these also occur in small quantity, and, as I am led to believe, have acquired their characteristics by filtration through masses of sandstone. Whatever the variety of petroleum may be, if exposed for a long time to the air it undergoes a spontaneous distillation, in which gases and vapors, existing or formed, escape, and solid residues are left. The nature of these solids varies with the petroleums from which they come, some producing asphaltum, others paraffine, others ozokerite, and so on through a long list of substances, which have received distinct names as mineral species, though rarely, if ever, possessing a definite and invariable composition. The change of petroleum to asphalt may be witnessed at a great number of localities. In Canada, the black asphaltic oil forms by its evaporation great sheets of hard or tarry asphalt, called gum beds, around the oil-springs. In the far West are numerous springs of petroleum, which are known to the hunters as “_tar springs_,” because of the accumulations about them of the products of the evaporation and oxidation of petroleum to tar or asphalt. Certain less common oils yield ozokerite as a solid, and considerable accumulations of this are known in Galicia and Utah.
Natural paraffine is less abundant, and yet in places it occurs in considerable quantity. Asphalt is the common name for the solid residue from the evaporation and oxidation of petroleum; and large accumulations of this substance are known in many parts of the world, perhaps the most noted of all being that of the “Pitch Lake”. of the Island of Trinidad; there, as everywhere else, the derivation of asphalt from petroleum is obvious, and traceable in all stages. The asphalts, then, have a common history in this, that they are produced by the evaporation and oxidation of petroleum. But it should also be said that they share the diversity of character of petroleums, and the term asphalt represents a group of substances of which the physical characters and chemical composition differ greatly in virtue of their derivation, and also differ from changes which they are constantly undergoing. Thus at the Pitch Lake in Trinidad, the central portion is a tarry petroleum, near the sides a plastic asphalt, and finally that which is of almost rock-like solidity. Hence we see that the solid residues from petroleum are unstable compounds like the coals and lignites, and in virtue of their organic nature are constantly undergoing a series of changes of which the final term is combustion or oxidation. From these facts we might fairly infer that asphalts formed in geological ages anterior to the present would exhibit characters resulting from still further distillation; that they would be harder and drier, i.e., containing less volatile ingredients and more fixed carbon. Such is, in fact, the case; and these older asphalts are represented by _Grahamite, Albertite_, etc., which I have designated as asphaltic coals. These are found in fissures and cavities in rocks of various ages, which have been more or less disturbed, and usually in regions where springs of petroleum now exist. The Albertite fills fissures in Carboniferous rocks in New Brunswick, on a line of disturbance and near oil-springs. Precisely the same may be said of the Grahamite of West Virginia. It fills a vertical fissure, which was cut through the sandstones and shales of the coal-measures; in the sandstones it remained open, in the shales it has been closed by the yielding of the rock. The Grahamite fills the open fissure in the sandstone, and was plainly introduced when in a liquid state. In the vicinity are oil springs, and it is on an axis of disturbance. From near Tampico, Mexico, I have received a hydrocarbon solid–essentially Grahamite, asphalt, and petroleum. These are described as occurring near together, and evidently represent phases of different dates in the same substance. I have collected asphaltic coals, very similar to Grahamite and Albertite in appearance and chemical composition, in Colorado and Utah, where they occur with the game associates as at Tampico. I have found at Canajoharie, New York, in cavities in the lead-veins which rut the Utica shale, a hydrocarbon solid which must have infiltrated into these cavities as petroleum, but which, since the remote period when the fissures were formed, has been distilled until it is now _anthracite_. Similar anthracitic asphalt or asphaltic anthracite is common in the Calciferous sand-rock in Herkimer County, New York, where it is associated with, and often contained in, the beautiful crystals of quartz for which the locality is famous. Here the same phase of distillation is reached as in the coke residuum of the petroleum stills.
Again, in some crystalline limestones, detached scales or crystals of _graphite_ occur, which are undoubtedly the product of the complete distillation of liquid hydrocarbons with which the rock was once impregnated. The remarkable purity of such graphite is the natural result of its mode of formation, and such cases resemble the occurrence of graphite in cast iron and basalt. The black clouds and bands which stain many otherwise white marbles are generally due to specks of graphite, the residue of hydrocarbons which once saturated the rock. Some limestones are quite black from the carbonaceous matter they contain (Lycoming Valley, Pa., Glenn’s Falls, N. Y., and Collingwood, Canada), and these are sold as black marbles, but if exposed to heat, such limestones are blanched by the expulsion of the contained carbon; usually a residue of anthracite or graphite is left, forming dark spots or streaks, as we find in the clouded and banded marbles.
Finally, the great work going on in Nature’s laboratory may be closely imitated by art; the differences in the results being simply the consequence of differing conditions in the experiments. Vegetable tissue has been converted artificially into the equivalents of lignite, coal, anthracite, and graphite, with the emission of vapors, gases, and oils closely resembling those evolved in natural processes. So petroleum may be distilled to form asphalt, and this in turn converted into Albertite and coke (i.e., anthracite). Grahamite has been artificially produced from petroleum by Mr. W. P. Jenney.
In the preceding remarks, no effort has been made even to enumerate all the so-called carbon minerals which have been described. This was unnecessary in a discussion of the relations of the more important groups, and would have extended this article much beyond its prescribed length. Those who care to gain a fuller knowledge of the different members of the various groups are referred to the admirable chapter on the “Hydrocarbon Compounds” in Dana’s Mineralogy.
It will, however, add to the value of this paper, if brief mention be made of a few carbon minerals of which the genesis and relations are not generally known, and in regard to which special interest is felt, such as the diamond, jet, the hydrocarbon jellies, “Dopplerite,” etc.
The diamond is found in the _debris_ of metamorphic rocks in many countries, and is probably one of the evolved products of the distillation of organic matter they once contained. Under peculiar circumstances it has apparently been formed by precipitation from sulphide of carbon or some other volatile carbon compound by elective affinity. Laboratory experiments have proved the possibility of producing it by such a process, but the artificial crystals are microscopic, perhaps only because a long time is required to build up those of larger size.
Jet is a carbonaceous solid which in most cases is a true lignite, and generally retains more or less of the structure of wood. Masses are sometimes found that show no structure, and these are probably formed from bitumen which has separated from the wood of which it once formed part, and which it generally saturates or invests. In some cases, however, these masses of jet-like substance are plainly the residuum of excrementitious matter voided by fishes or reptiles. These latter are often found in the Triassic fish-beds of Connecticut and New Jersey, and in the Cretaceous marls of the latter State.
The discovery of a quantity of hydrocarbon jelly, recently, in a peat-bed at Scranton, Pa., has caused some wonder, but similar substances (Dopplerite, etc.) have been met with in the peat-beds of other countries; and while the history of the formation of this singular group of hydrocarbons is not yet well understood, and offers an interesting subject for future research, we have reason to believe that these jellies have been of common occurrence among the evolved products of the decomposition of vegetable tissue in all ages.
The fossil resins–often erroneously called gums–amber, kauri, copal, etc., though interestingly related to the hydro-carbons enumerated on the preceding pages, form no essential part of the series, and demand only the briefest notice here.
_Amber_ is the resin which exuded from certain coniferous trees that, in Tertiary times, grew abundantly in northern Europe. The leaves and trunks of these trees have generally perished; but masses of their resin, more enduring, buried in the earth on the shores of the Baltic, have in the lapse of time changed physically and chemically, and have become fitted for the ornamental purposes for which they have been used by all civilized nations.
_Kauri_ is the resin of _Dammara australis_, a living coniferous tree of New Zealand, and the “gum” is dug from the earth on the sites of forests which have now disappeared.
_Copal_ is a commercial name given to the resins of several different trees, but the most esteemed, and indeed the only true copal, is the product of _Trachylobium Mozambicense_, a tree which grows along the Zanzibar coast, and has left its resin buried in the sands of old raised beaches which it has abandoned.
The diversity of character which the fossil resins exhibit shows the complexity of the vital processes in operation in the vegetable kingdom, and gives probability to the theory that some of the differences we find in the carbon minerals are due to differences in the plants from which they have been derived.
The variations in the physical and chemical characters of different coals from the same basin, and from different parts of the same stratum, have been sometimes credited to the same cause; but they are probably in greater degree due to the differences in the conditions under which these varieties have been formed.
Cannel coal, as I have shown elsewhere (_Amer. Jour. Science_, March, 1857), is completely macerated vegetable tissue which was deposited as carbonaceous mud at the bottom of lagoons in the coal-marshes.
Caking coals were probably peat, which accumulated under somewhat uniform conditions, was constantly saturated with moisture, and became a comparatively homogeneous and partially gelatinous carbonaceous mass; while the open-burning coals which show a distinctly laminated structure and consist of layers of pitch-coal, alternating with bands of mineral charcoal or cannel, seem to have been formed in alternating conditions, of more or less moisture, and the bituminous portions are inclosed in cells or are separated by partitions, so that the mass does not melt down, but more or less perfectly holds its form when exposed to heat.
The generalities of the origin and relations of the carbon minerals have now been briefly considered; but a review of the subject would be incomplete without some reference to the theories which have been advanced by others, that are in conflict with the views now presented. There have always been some who denied the organic nature of the mineral hydrocarbons, but it has been regarded as a sufficient answer to their theories, that chemists and geologists are generally agreed in saying that no instances are known of the occurrence in nature of hydrocarbons, solid, liquid, or gaseous, in which the evidence was not satisfactory that they had been derived from animal or vegetable tissue. A few exceptional cases, however, in which chemists and geologists of deserved distinction have claimed the possibility and even probability of the production of marsh gas, petroleum, etc., through inorganic agencies, require notice.
In a paper published in the _Annales de Chimie et de Physique_, Vol. IX., p.481, M. Berthelot attempts to show that the formation of petroleum and carbureted hydrogen from inorganic substances is possible, if it be true, as suggested by Daubre, that there are vast masses of the alkaline metals–potassium, sodium, etc.–deeply buried in the earth, and at a high temperature, to which carbonic acid should gain access; and he demonstrates that, these premises being granted, the formation of hydrocarbons would necessarily follow.
But it should be said that no satisfactory evidence has ever been offered of the existence of zones or masses of the unoxidized alkaline metals in the earth, and it is not claimed by Berthelot that there are any facts in the occurrence of petroleum and carbureted hydrogen in nature which seem to exemplify the chemical action which he simply claims is theoretically possible. Berthelot also says that, in most cases, there can be no doubt of the organic origin of the hydrocarbons.
Mendeleeff, in the _Revue Scientifique_, 1877, p. 409, discusses at considerable length the genesis of petroleum, and attempts to sustain the view that it is of inorganic origin. His arguments and illustrations are chiefly drawn from the oil wells of Pennsylvania and Canada, and for the petroleum of these two districts he claims an inorganic origin, because, as he says, there are no accumulations of organic matter below the horizons at which the oils and gases occur. He then goes into a lengthy discussion of the possible and probable source of petroleum, where, as in the instances cited, an organic origin “is not possible.” It is a sufficient answer to M. Mendeleeff to say, that beneath the oil bearing strata of western Pennsylvania are sheets of bituminous shale, from one hundred to five hundred feet in thickness, which afford an adequate, and it may be proved the true source, of the petroleum, and that no petroleum has been found below these shales; also that the oil-fields of Canada are all underlain by the Collingwood shales, the equivalent of the Utica carbonaceous shales of New York, and that from the out-crops of these shales petroleum and hydrocarbon gases are constantly escaping. With a better knowledge of the geology of the districts he refers to, he would have seen that the facts in the cases he cites afford the strongest evidence of the organic origin of petroleum.
Among those who are agreed as to the organic origin of the hydrocarbons, there is yet some diversity of opinion in regard to the nature of the process by which they have been produced.
Prof. J. P. Lesley has at various times advocated the theory that petroleum is indigenous in the sand-rocks which hold it, and has been derived from plants buried in them. (“Proc. Amer. Philos. Soc.,” Vol. X., pp. 33, 187, etc.)
My own observations do not sanction this view, as the limited number of plants buried in the sandstones which are now reservoirs of petroleum must always have borne a small proportion in volume to the mass of inorganic matter; and some of those which are saturated with petroleum are almost completely destitute of the impressions of plants.
In all cases where sandstones contain petroleum in quantity, I think it will be found that there are sheets of carbonaceous matter below, from which carbureted hydrogen and petroleum are constantly issuing. A more probable explanation of the occurrence of petrolem in the sandstones is that they have, from their porosity, become convenient receptacles for that which flowed from some organic stratum below.
Dr. T. Sterry Hunt has regarded limestones, and especially the Niagara and corniferous, as the principal sources of our petroleum; but, as I have elsewhere suggested, no considerable flow of petroleum has ever been obtained from the Niagara limestone, though at Chicago and Niagara Falls it contains a large quantity of bituminous matter; also, that the corniferous limestone which Dr. Hunt has regarded as the source of the oil of Canada and Pennsylvania is too thin, and too barren of petroleum, or the material out of which it is made, to justify the inference.
The corniferous limestone is never more than fifty or sixty feet thick, and does not contain even one per cent. of hydrocarbons; and in southern Kentucky, where oil is produced in large quantity, this limestone does not exist.
That many limestones are more or less charged with petroleum is well known; and in addition to those mentioned above, the Silurian limestone at Collingwood, Canada, may be cited as an example. As I have elsewhere shown, we have reason to believe that the petroleum here is indigenous, and has been derived, in part, at least, from animal organisms; but the limestones are generally compact, and if cellular, their cavities are closed, and the amount of petroleum which, under any circumstances, flows from or can be extracted from limestone rock is small. On the other hand, the bituminous shales which underlie the different oil regions afford an abundant source of supply, holding the proper relations with the reservoirs that contain the oil, and are spontaneously and constantly evolving gas and oil, as may be observed in a great number of localities. For this reason, while confessing the occurrence of petroleum and asphaltum in many limestones, I am thoroughly convinced that little or none of the petroleum of commerce is derived from them.
Prof. S.F. Peckham, who has studied the petroleum field of southern California, attributes the abundant hydrocarbon emanations in that locality to microscopic animals. It is quite possible that this is true in this and other localities, but the bituminous shales which are evidently the sources of the petroleum of Pennsylvania, Ohio, Kentucky, etc., generally contain abundant impressions of sea weeds, and indeed these are almost the only organisms which have left any traces in them. I am inclined, therefore, now, as in my report on the rock oils of Ohio, published in 1860, to ascribe the carbonaceous matter of the bituminous shales of Pennsylvania and Ohio, and hence the petroleum derived from them, to the easily decomposed cellular tissue of algae which have in their decomposition contributed a large percentage of diffused carbonaceous matter to the sediments accumulating at the bottom of the water where they grew. In a recent communication to the National Academy of Sciences, Dr. T. Sterry Hunt has proposed the theory that anthracite is the result of the decomposition of vegetable tissue when buried in porous strata like sandstone; but an examination of even a few of the important deposits of anthracite in the world will show that no such relationship as he suggests obtains.
Anthracite may and does occur in sedimentary rocks of varied character, but, so far as my observation has extended, never in quantity in sandstone. In the Lower Silurian rocks anthracite occurs, both in the Old World and in the New, where no metamorphism has affected it, and where it is simply the normal result of the long continued distillation of plant tissue; but the anthracite beds which are known and mined in so many countries are the results of the metamorphism of coal-beds of one or another age, by local outbursts of trap, or the steaming and baking of the disturbed strata in mountain chains, numerous instances of which are given on a preceding page.
M. Mendeleeff, in his article already referred to, misled by a want of knowledge of the geology of our oil-fields, and ascribing the petroleum to an inorganic cause, connects the production of oil in Pennsylvania and Caucasia with the neighboring mountain chains of the Alleghanies and the Caucasus; but in these localities a sufficient amount of organic matter can be found to supply a source for the petroleum, while the upheaval and loosening of the strata along lines parallel with the axes of elevation has favored the decomposition (spontaneous distillation) of the carbonaceous strata. It should be distinctly stated, also, that no igneous rocks are found in the vicinity of productive oil-wells, here or elsewhere, and there are no facts to sustain the view that petroleum is a volcanic product.
In the valley of the Mississippi, in Ohio, Illinois, and Kentucky, are great deposits of petroleum, far removed from any mountain chain or volcanic vent, and the cases which have been cited of the limited production of hydrocarbons in the vicinity of, and probably in connection with, volcanic centers may be explained by supposing that in these cases the petroleum is distilled from sedimentary strata containing organic matter by the proximity of melted rock, or steam.
Everything indicates that the distillation which has produced the greatest quantities of petroleum known was effected at a low temperature, and the constant escape of petroleum and carbureted hydrogen from the outcrops of bituminous shales, as well as the result of weathering on the shales, depriving them of all their carbon, shows that the distillation and complete elimination of the organic matter they contain may take place at the ordinary temperature.
* * * * *
ESTIMATION OF SULPHUR IN IRON AND STEEL.
By GEORGE CRAIG.
For wellnigh two years I have been estimating sulphur in iron and steel by a modification of the evolution process, which consists in passing the evolved gases through an ammoniacal solution of peroxide of hydrogen, which oxidizes the sulphureted hydrogen to sulphuric acid, which latter is estimated as usual. The _modus operandi_ is as follows:
[Illustration]
100 grains of the iron or steel are placed in the 10 oz. flask, a, along with 1/2 oz. water; 11/2 oz. hydrochloric acid are added from the stoppered funnel, b, in such quantities at a time as to produce a moderate evolution of gas through the nitrogen bulb, c, which contains 1/8 oz. (20 vols.) peroxide of hydrogen and 1/2 oz. ammonia. The tube, d, is to condense the bulk of the hydrochloric acid which distills over during the operation. When all the acid has been added and the evolution of gas becomes sluggish, heat is applied and the liquid boiled till all action ceases. Air is blown through the aparatus for a few minutes and the contents of c and d washed into a small beaker and acidified with hydrochloric acid, boiled, barium chloride added, and the barium sulphate filtered off after standing a short time. A blank experiment must be done with each new lot of peroxide of hydrogen obtained, which always gives under 0.1 barium sulphate with me.
The whole operation is finished within two hours, the usual oxidation process occupying nearly two days; and the results obtained are invariably slightly higher than by the oxidation processes.
Until lately I have always added excess of chlorate of potash to the residue left in a, evaporated it nearly to dryness, diluted, filtered, and added chloride of barium to the diluted filtrate, but only once have I obtained a trace of precipitate after standing 48 hours, and the pig-iron in that case contained 8 per cent. of silicon, so that all the sulphur is evolved during the process. It has been objected to the evolution process that when the iron contains copper all the sulphur is not evolved, but theoretically it ought to be evolved whether copper is present or not; and to test the point I fused 3 lb. of ordinary Scotch pig-iron with some copper for half an hour in a Fletcher’s gas furnace. No copper could be detected in the iron by mere observation with a microscope, but it gave on analysis 0.225 per cent. of copper, and on estimating the sulphur in it by the above process and by oxidation with chlorate of potash and hydrochloric acid, using 100 grains in each case, and performing blank experiments, I found:
By peroxide of hydrogen process 0.0357 per cent. By oxidation (KClO_{3} and HCl) process, 0.0302 “
so that even in highly cupriferous pig-iron all the sulphur is evolved on treatment with strong hydrochloric acid.–_Chem. News_.
* * * * *
THE AIR IN RELATION TO HEALTH.
[Footnote: Abstract of a lecture before the Master Plumbers’ Association, New York, Nov. 2. 1882.]
By Prof. C. F. CHANDLER.
It is only about one hundred years since the first important facts were discovered which threw light upon the chemistry of atmosphere. It was in 1774 that Dr. Priestley, in London, and Scheele, in Sweden, discovered the vital constituents of the atmosphere–the oxygen gas which supports life. The inert gas, nitrogen, had been discovered a year or two before. When we examine our atmosphere, we find it is composed of oxygen and nitrogen. The nitrogen constitutes no less than 80 per cent, of the atmosphere; the remaining 20 percent, consists of oxygen, so that the atmosphere consists almost entirely of these two gases, odorless and colorless and invisible. The atmosphere is, however, never free from moisture; a certain amount of aqueous vapor is always present. The quantity can hardly be stated, as it varies from day to day and month to month; it depends upon the temperature and other conditions. Then we have the gas commonly called carbonic acid in extremely minute quantities, about one part in 2,500, or four one-hundredths of one per cent. A small quantity of ammonia and a small quantity of ozone are also present.
Besides these gases which have been enumerated, and which play an important part in supporting life in both the kingdoms of nature, we find a great many solids. Every housewife knows how dust settles upon everything about the house. This dust has recently been the subject of most active study, and it proves to be quite as important as the vital oxygen that actually supports life. When we examine this dust–and it falls everywhere, not only in the city streets, but upon the tops of mountains, upon the deck of the ocean steamer, and the Arctic snow–we find some of it does not belong to the earth, and, as it is not terrestrial, we call it cosmical. And when it falls in large pieces we call it a meteorite or shooting star. When the Challenger crossed the Atlantic, and soundings were made in the deep sea, in the mud that was brought up and examined there were found various little particles that were not terrestrial. They were dust particles that were dropped into the atmosphere of the earth from outer space. Then we have terrestrial dust, and we divide that into mineral and organic. The mineral consists chiefly of clay, sand, and, near the ocean, salt. Then we have organic matter. Some of this is dead leaves which have been ground to powder. Animal matter has also become dry and reduced to powder, and we actually find the remains of animals and plants floating upon the atmosphere, especially in the city. Examinations of the dust which had collected upon the basement and higher windows of a Fifth avenue residence showed that the dust upon the basement floor was chiefly composed of sand. And the higher up I went, the smaller proportion of sand and a larger proportion of animal matter, so that the dust that blows into our faces is largely decomposing animal substance.
But we have a living matter in the atmosphere. We often notice in the summer, after a rain, that the ground is yellow. On gathering up the yellow powder and examining it under the microscope, we find that it consists of pollen. The pollen of rag weed and other plants is supposed to be the cause of hay fever. But we also have something far more important in the germs of certain classes of vegetation. The effects are familiar. If food is put away, it becomes mouldy. This mould is a peculiar kind of vegetation which is called a fungus, and the plants fungi. In order for this mould to develop a certain temperature and a certain degree of moisture are necessary. Our food, we say, decays. Now, what we call decay is really the growth of these fungi. Animal and vegetable substances which these fungi seize upon are destroyed. All ordinary fermentations and putrefactions are due to mould fungi, yeast plants, or bacteria, and liquids undergoing these processes carry these fungi and their germs wherever they go. The refuse of the city pollutes the air. You have only to pass along any street to find more or less rubbish. That furnishes the nidus for the growth and development of these germs, and until we adopt better methods of getting rid of that refuse, we never shall have the air of this city in the condition that it should be.
One of the most constant sources of the pollution of the air in inhabited localities is the decomposition that takes place in the ground. Refuse of every kind gets into it. Our sewers are leaky, and putrefaction is constantly going on. The soil down to the limit of the ground water contains a large amount of air. This air, when the atmospheric pressure in the house is diminished, is drawn in with such organic impurities as it contains. A cement floor in the cellar is not a protection against this entrance of the ground air, for the cement is porous to the passage of air, but a remedy may be found by laying on the cement a covering of coal tar pitch, in which bricks are set on edge, the spaces between the bricks are filled with the melted pitch, and the bricks then covered with coal tar pitch. When the house is building, the foundation walls should also be similarly coated, outside as well as inside. Such a cellar floor was considered to be absolutely impervious to ground air and moisture. The lecturer had recently laid this floor in his own house with the greatest success. The atmosphere of the entire house is improved, and the expense is very moderate. Another source of the contamination of the air of houses is the heating apparatus. Stoves and furnaces, however well constructed at first, will, from the contraction and expansion of the metal, soon allow the escape of coal gas, and this danger is greatly increased by the use of dampers in the stove-pipe. When, to regulate the fire, the damper in the pipe is closed, the gases, having their passage to the chimney cut off, will escape through any cracks or openings in the stove into the room. Prof. Chandler, having kept a record of accidents from this cause, had accumulated a formidable list of suffocations due to the use of the damper. The danger was now somewhat lessened by providing dampers with perforations in the center, which allowed the gases to escape when the damper was closed. As regards the maintenance of pure air in houses, the preference was given to the open fire-place. The hot-air furnace deriving a supply of pure air from out of doors was, when properly constructed, a very satisfactory method of heating, but in city houses the mistake was often made of carrying the cold air duct of the furnace to the front of the house, where it was exposed to the dust of the streets. It should be taken from the rear end of the house, and carried some distance above the surface of the yard. It was an excellent expedient to insert in the cold air duct a wire screen to hold a layer of cotton to retain the floating impurities which might enter the air-box. This could be removed from time to time, and the cotton replaced. Steam heating has been objected to by many for reasons in no wise due to the apparatus, but to neglect in the use of it. The complaint of closeness where steam is used is due to the fact that a room containing a steam radiator can be heated with every door and window closed, and no fresh air admitted, while with stoves and open fire-places a certain quantity of fresh air must be admitted to maintain the fire. Where radiators are used, the ventilation of the rooms should, therefore, be looked after. Again, the complaint that steam apparatus has an unpleasant odor is due to the fact that the radiators are allowed to become covered with dust, which is cooked, and gives rise to the smells complained of. The radiator should be from time to time cleaned. When these precautions are taken, no means of heating is more satisfactory than steam.
Sewer gas is another source of contamination; this is a very indefinite term, to which formerly many false and exaggerated properties of causing specific diseases were attributed. It is now, however, recognized to mean simply the air of sewers, generally not differing very greatly from common air, containing a certain proportion of marsh gas, carbonic acid, and sulphureted hydrogen, etc. No one of these gases, however, is capable of producing the diseases attributed to sewer gas. Careful research has shown that it is the sewage itself, containing germs of specific disease, which is added to the air in the sewer by the breaking of bubbles of gas on its surface, which is the cause of the diseases associated with sewers.
An intimate connection is believed to exist between the germs of sewer air and diphtheria, and probably also between sewer air and scarlet fever. This sewer gas is to be excluded from our houses by proper systems of plumbing, and to such an extent have these now been perfected, that there is no objection to having plumbing fixtures in all parts of the house. This opinion has lately been objected to in the _Popular Science Monthly_, as it was at a meeting of the Academy of Medicine last spring, but on wholly insufficient grounds.
The objectors all insist that a trap will allow sewer gas to pass through it, and the experiments made at the Academy of Medicine showed that sulphureted hydrogen gas, etc., would so pass. The advocates of the trap have never denied that the water seal would absorb gases on one side and give them off on the other, but they do deny that, in the conditions existing in good plumbing, such gases will be given off in quantities to do any damage, and they confidently assert that the germ which is the dangerous element will not pass the seal at all. Pumpelly investigated the matter for the National Board of Health, and in no instance was he able to make the germ pass the seal of the trap. It is now proposed to set up against the weight of this scientific testimony the results of an investigator in Chicago, whose work was at once appropriated as an advertisement by stock jobbing disinfectant companies in a manner which raises a suspicion that the investigation was made in their interest. He described tersely the essentials of good plumbing, the necessity of a trap on the house drain, the ventilation of the soil-pipe, and the ventilation of the trap against siphonage. Of the first, he said that it offered protection to each householder against the entrance into his house of the germs of a contagious disease which passed into the common sewer from the house of a neighbor. Were the trap dispensed with, the contagion in the sewer would have free entrance into the houses connecting with it.
Prof. Chandler, in conclusion, alluded to the cordial relations now existing between the Board of Health and the majority of the master plumbers of the city. He said that for himself his opinion of the craft had greatly risen during his intimate connection with plumbers the last two years. He thought the majority of the jobs now done in the city are well executed. He believed that the Board of Health had not been obliged to proceed against more than eight master plumbers since the new law went into force. He called upon the Association to adopt a “code of ethics,” which should define what an honest plumber can do and cannot do, and he illustrated his meaning by citing an extraordinary case of fraudulent workmanship which had been recently reported to him. His remarks on this point were greeted with frequent outbursts of applause.
* * * * *
THE PLANTAIN AS A STYPTIC.
The following abstract of a paper read by Dr. Quinlan at the recent British Pharmaceutical Congress, may prove of interest to medical readers in this country, where the plant mentioned is a common weed:
“About a year ago Dr. Quinlan had seen the chewed leaves of the _Plantago lanceolata_ successfully used to stop a dangerous hemorrhage from leech bites in a situation where pressure could not be employed. He had searched out the literature of the subject, and found that, although this herb is highly spoken of by Culpepper and other old writers as a styptic, and alluded to as such in the plays of Shakespeare, its employment seems to have died out. Professor Quinlan described the suitable varieties of plantain, and exhibited preparations which had been made for him by Dr. J. Evans, of Dublin, State apothecary. They dried leaves and powdered leaves, conserved with glycerine, for external use; the juice preserved by alcohol, as also by glycerine, for internal use; and a green extract. He gave an account of the chemistry of the juice, from which it appeared that it was not a member of the tannin series; and also described its physiological effect in causing a tendency to stasia in the capillaries of the tail of a goldfish, examined with a microscopic power of 400 X. He regarded its styptic power as partly mechanical and partly physiological. The juice, in large doses, he had found useful in internal hemorrhages. The knowledge of the properties of this plant he thought would be useful in cases of emergency, because it could be obtained in any field and by the most uninstructed persons.”
* * * * *
BACTERIA.
Bacteria, whether significant of disease or decline of health, are found more or less numerous in everything we eat and drink. The germs or spores of many kinds, known as _termo_, _lineola_, tenue, spirillum, vibriones, etc, exist in almost infinite numbers; some of the smallest are too small to be seen by the highest powers, which, being lodged in all vegetable and animal substances, spring into life and develop very rapidly under favorable circumstances. They develop most rapidly when decomposition commences, and seem to indicate the degree or activity of that decomposition, also hastening the same. They are found most numerous in the feces, and usually fully developed in the fresh evacuations of persons of all ages. They may be seen plainly under a thin glass with high powers with strong or clear light, when the material is much diluted with water.
These bacteria appear almost as numerously, yet more slowly, in urine, either upon exposure to air or when freshly evacuated, when the general health of the individual is declining, or any tendency to decomposition. A diagnosis can be aided very greatly by a study of these bacteria, as they indicate or determine the vitality, vigor, and purity of the system, whether more or less subject to disease, even before any signs of disease appear. They seem to preindicate the hold of the life force on the material, and always appear when that force is broken. Their relative quantity found in feces is as a barometric indication of the general health or some particular disturbance, and it is surprising how very fast they multiply while simply passing the intestines under circumstances favorable for their growth. These forms, so small, are important, because so very numerous, and their study has been, perhaps, avoided by many; yet they certainly mean something and effect something, even the non-malignant varieties as mentioned above, and it is certainly worth while to continue to study their meaning, even beyond what has already been written by others on the subject.–_J.M. Adams, in The Microscope_.
* * * * *
THE SOY BEAN
(_Soja hispida_.)
A good deal of attention has lately been directed to this plant in consequence of the enormous extent to which it is cultivated in China for the sake of the small seeds which it produces, and which are known as soy beans. These vary considerably in size, shape, and color, according to the variety of the plant which produces them. They are for the most part about the size and shape of an ordinary field pea, and, like the pea, are of a yellow color; some, however, are of a greenish tint. These seeds contain a large quantity of oil, which is expressed from them in China and used for a variety of purposes. The residue is moulded with a considerable amount of pressure into large circular cakes, two feet or more across, and six inches or eight inches thick. This cake is used either for feeding cattle or for manuring the land; indeed, a very large trade is done in China with bean cake (as it is always called) for these purposes. The well-known sauce called soy is also prepared from seeds of this bean. The plant generally known as Soja hispida is by modern botanists referred to Glycine soja. It is an erect, hairy, herbaceous plant. The leaves are three-parted and the papilionaceous flowers are born in axillary racemes. It is too tender for outdoor cultivation in this country, but, has been recommended for extended growth in our colonies as a commercial plant. The plants are readily used from seed.–_J.R.F., in The Garden_.
[Illustration: THE SOY BEAN. _(Soja Lispida)_]
* * * * *
ERICA CAVENDISHIANA.
The plant of which the illustration is given is one of those fine specimens which has made the collection of J. Lawless, Esq., The Cottage, Exeter, famous all over the south and west of England. It is only one specimen among a considerable collection of hard-wooded plants which are cultivated and trained in first rate style by Mr. George Cole, the gardener, one of the most successful plant growers of the day. The plant was in the winning collection of Mr. Cole exhibited at the late spring show held at Plymouth.–_The Gardeners’ Chronicle_.
[Illustration: ERICA CAVENDISHIANA.]
* * * * *
PHILESIA BUXIFOLIA.
We figure this plant, not as a novelty, but for the purpose of showing what a fine thing it is when grown under propitious circumstances. Generally, we see it more or less starved in the greenhouse, and even when planted out in the winter garden its flowers lack the size and richness of color they attain out-of-doors. It comes from the extreme south of South America, which accounts for its hardihood, and is a near ally of the Lapageria: the latter is remarkable for withstanding even the noxious fumes of the copper smelting works in Chili, and as the Philesia has similar tough leaves, it is probable that it would support the vitiated atmosphere of a town better than most evergreens. In any case, there is no reasonable doubt but that, if cultivators would take the necessary pains, they might select perfectly hardy varieties both of the Lapageria and of the Philesia. As it is, we can only call the Philesea half-hardy north of the Thames, while the Lapageria is not even that. The curious Philageria, raised in Messrs. Veitch’s nursery and described and figured in our columns in 1872, p. 358, is a hybrid raised between the two genera. For the specimen of Philesia figured we are indebted to Mr. Dartnall.–_The Gardeners’ Chronicle_.
[Illustration: PHILESIA BUXIFOLIA–HARDY SHRUB–FLOWERS, ROSE PINK.]
* * * * *
MAHOGANY.
The mahogany tree, says the _Lumber World_, is a native of the West Indies, the Bahamas, and that portion of Central America that lies adjacent to the Bay of Honduras, and has also been found in Florida. It is stated to be of moderately rapid growth, reaching its full maturity in about two hundred years. Full grown, it is one of the monarchs of tropical America. Its trunk, which often exceeds forty feet in length and six in diameter, and massive arms, rising to a lofty height, and spreading with graceful sweep over immense spaces, covered with beautiful foliage, bright, glossy, light, and airy, clinging so long to the spray as to make it almost an evergreen, present a rare combination of loveliness and grandeur. The leaves are small, delicate, and polished like those of the laurel. The flowers are small and white, or greenish yellow. The fruit is a hard, woody capsule, oval, not unlike the head of a turkey in size and shape, and contains five cells, in each of which are inclosed about fifteen seeds.
The mahogany tree was not discovered till the end of the sixteenth century, and was not brought into European use till nearly a century later. The first mention of it is that it was used in the repair of some of Sir Walter Raleigh’s ships, at Trinidad, in 1597. Its finely variegated tints were admired, but in that age the dream of El Dorado caused matters of more value to be neglected. The first that was brought to England was about 1724, a few planks having been sent to Dr. Gibbons, of London, by a brother who was a West Indian captain. The doctor was erecting a house, and gave the planks to the workmen, who rejected them as being too hard. The doctor then had a candle-box made of the wood, his cabinet-maker also complaining of the hardness of the timber. But, when finished, the box became an object of general curiosity and admiration. He had one bureau, and her Grace of Buckingham had another, made of this beautiful wood, and the despised mahogany now became a prominent article of luxury, and at the same time raised the fortunes of the cabinet-maker by whom it had been so little regarded. Since that lime it has taken a leading rank among the ornamental woods, having come to be considered indispensable where luxury is intended to be indicated.
A few facts will furnish a tolerably distinct idea of the size of this splendid tree. The mahogany lumbermen, having selected a tree, surround it with a platform about twelve feet above the ground, and cut it above the platform. Some twelve or fifteen feet of the largest part of the trunk are thus lost. Yet a single log not unfrequently weighs from six or seven to fifteen tons, and sometimes measures as much as seventeen feet in length and four and a half to five and a half feet in diameter, one tree furnishing two, three, or four such logs. Some trees have yielded 12,000 superficial feet, and at average price pieces have sold for $15,000. Messrs. Broadwood London, pianoforte manufacturers, paid L3,000 for three logs, all cut from one tree, and each about fifteen feet long and more than three feet square. The tree is cut at two seasons of the year–in the autumn and about Christmas time. The trunk, of course, furnishes timber of the largest dimensions, but that from the branches is preferred for ornamental purposes, owing to its closer grain and more variegated color.
In low and damp soil its growth is rapid; but the most valuable trees grow slowly among rocks on sterile soil, and seem to gather compactness and beauty from the very struggle which they make for an existence. In the Bahamas, in the most desolate regions, once flourished that curiously veined and much esteemed variety once known in Europe as “Madeira wood,” but which has long since been exterminated. Jamaica, also, which used to be a fruitful source of mahogany, and whence in 1753 not less than 521,000 feet were shipped, is now almost depleted. That which is now furnished from there is very inferior, pale, and porous, and is less esteemed than that of Cuba, San Domingo, or Honduras.
In a dry state mahogany Is very durable, and not liable to the attack of worms, but, when exposed to the weather it does not last long. It would therefore make excellent material for floors, roofs, etc., but its costliness limits its utility in this direction, and it is chiefly employed for furniture, doors, and a few other articles of joinery, for which it is among the best materials known. It has been used for sashes and window frames, but is not desirable for this purpose on account of the ease with which it is affected by the weather. It has also been used in England to some extent for the framing of machinery in cotton-mills. Its color is a reddish brown of different shades and luster, sometimes becoming a yellowish brown, and often much veined and mottled with darker shades of the same color. Its texture is uniform, and the rings indicating its annual growth are not very distinct. The larger medullary rays are absent, but the smaller ones are often very distinct, with pores between them. In the Jamaica woods these pores are often filled with a white substance, but in that brought from Central America they are generally empty. It has neither taste nor odor, shrinks very slightly, and warps, it is said, less than any other wood.
The variety called Spanish mahogany comes from the West Indies, and is in smaller logs than the Honduras mahogany, being generally about two feet square and ten feet long. It is close grained and hard, generally darker than the Honduras, free from black specks, and sometimes strongly marked; the pores appear as though chalk had been rubbed into them.
The Honduras mahogany comes in logs from two to four feet square and twelve to fourteen long; planks have been obtained seven feet wide. Its grain is very open and often irregular, with black or gray specks. The veins and figures are often very distinct and handsome, and that of a fine golden color and free from gray specks is considered the best. It holds the glue better than any other wood. The weight of a cubic foot of mahogany varies from thirty-five to fifty-three pounds. Its strength is between sixty-seven and ninety-six, stiffness seventy-three to ninety-three, and toughness sixty-one to ninety-nine–oak being considered as one hundred in each case.
There are three other species of the genus _Swietania_ besides the mahogany tree, two of them natives of the East Indies. One is a very large tree, growing in the mountainous parts of central Hindostan, and rises to a great height, throwing out many branches toward the top. The head is spreading and the leaves bear some resemblance to those of the American species. The wood is a dull red, not so beautiful as that known to commerce, but harder, heavier, and more durable. The natives of India consider it the most durable timber which their forests afford, and consequently use it, when it can be procured, wherever strength and durability are particularly desired. The other East Indian species is found in the mountains of Sircars, which run parallel to the Bay of Bengal. The tree is not so large as any of the other species described, and the wood is of much different appearance, being of a deep yellow, considerably resembling box. The grain is close, and the wood both heavy and durable. The third species, known as African mahogany, is brought from Sierra Leone. It is hard and durable, and used for purposes requiring these properties in an eminent degree. If, however, the heart of the tree be exposed or crossed in cutting or trimming the timber, it is very liable to premature and rapid decay.
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ANIMALS AND THE ARTS.
In many of the museums efforts are made to perfect economic collections of animals, so as to show how they can be applied to advantage in the arts and sciences. The collection and preparation of the corals, for example, form an important industry. The fossil corals are richly polished and set in studs and sleeve-buttons, forming rich and ornamental objects. The fossil coral that resembles a delicate chain has been often copied by designers, while the red and black corals have long been used. The best fisheries are along the coasts of Tunis, Algeria, and Morocco, from 2 to 10 miles from shore, in from 30 to 150 fathoms. Good coral is also common at Naples, near Leghorn and Genoa, and on various parts of the sea, as Sardinia, Corsica, Catalonia, Provence, etc. It ranges in color from pure white through all the shades of pink, red, and crimson. The rose pink is most valued. For a long time Marseilles was the market, but now Italy is the great center of the trade, the greater number of boats hailing from Torre del Greco, while outside persons are forced to pay a heavy tax. The vessels are schooners, lateen-rigged, from three to fourteen tons. Large nets are used, which, during the months between March and October, are dragged, dredge-like, over the rocks. A large crew will haul in a season from 600 to 900 pounds. To prevent the destruction of the industry, the reef is divided into ten parts, only one being worked a year, and by the time the tenth is reached the first is overgrown again with a new growth. In 1873 the Algerian fisheries alone, employing 3,150 men, realized half a million of dollars. The choice grades are always valuable, the finest tints bringing over $5 per ounce, while the small pieces, used for necklaces, and called collette, are worth only $1.50 per ounce. The large oval pieces are sent to China, where they are used as buttons of office by the mandarins.
THE CONCH-SHELL.
Somewhat similar in appearance to coral is the conch jewelry, sets of which have been sold for $300. The tint is exquisite, but liable to fade when exposed to the sun. It is made from the great conch, common in Southern Florida and the West Indies. The shells are imported into Europe by thousands, and cut up into studs, sleeve-buttons, and various articles of ornament. These conches are supposed to be the producers of pink pearls, but I have opened hundreds of them and failed to find a single pearl. The conch shell is used by the cameo cutter. Rome and Paris are the principal seats of the trade, and immense numbers of shell cameos are imported by England and America, and mounted in rings, brooches, etc. The one showing a pale salmon-color upon an orange ground is much used. In 1847, 300 persons worked upon these shells in Paris alone, the number of shells used being immense. In Paris 300,000 helmet-shells were used in one year, valued at $40,000 of the bull’s mouth, 80,000, averaging a little over a shilling apiece, equal to $34,000. Eight thousand black helmets were used, valued at $9,000. The value of the large cameos produced in Paris in the year 1847 was about $160,000, and the small ones $40,000. In the Wolfe collection of shells at the Museum of Natural History, Central Park, is a fine specimen of