Chapter X: MISCELLANEOUS.--New Monumental Statue and Landing Place (3)

Koenig also made a very ingenious modification of the siren for the purpose of enabling Seebeck to sound simultaneously notes whose vibrations had any given ratio. It is furnished for this purpose with eight disks, each of which contains a given number of circles of holes arranged at different angular distances. A description of this instrument, which is also the property of the Stevens Institute, and of Seebeck's experiments is thus given in a letter by Koenig himself.

I.

_Effects produced when the isochronism of the shocks is not perfect_.

A.

In order to produce a note, the succession of shocks must not deviate much from isochronism.

If the isochronism is but little impaired, we obtain a note corresponding to the mean interval of the shocks.

If the intervals between the shocks are alternately t and t', and if the difference between t and t' is slight, we obtain the two notes t+t' and (t+t')/2. If the intervals between the shocks are alternately t, t', and t'', we obtain the two notes t+t'+t'' and (t+t'+t")/3.

Disk No. 1 has--

On circle No. 1 12 holes, angular distances t=30°
" " 2 24 " " " 15°
" " 3 36 " " " 10°
" " 4 36 " at irregular distances.
" " 5 36 " distances t= 10½°, t'=l0°,t''=9½°
" " 6 36 " " 11° 10° 9°
" " 7 36 " " 16° 14°
" " 8 36 " " 16½° 13½°

Circle No. 8 produces the two notes of circles 1 and 2; circle No. 7 the same, but the low note is stronger than in 8.

Circle 6 produces the notes of circles 1 and 3, and so does circle 5, but in the latter the low note is stronger than in 6.

Circle 4 produces a noise approximating only to the note of circle 3.

By pulling out one of the buttons of the wind chest, we admit the air through eleven holes at a time, having an angular distance of 30° and directing it against the corresponding circle of holes on the turning disk. If the arrangement of holes is not repeated identically twelve times on the same circle, we cannot, of course, make use of the above arrangements of holes of the wind tube, and we must then employ one of the movable brass tubes, which communicate with the interior of the wind chest by means of rubber tubes and stopcocks. The experiment with disk 1, circle 4, for example, requires the use of one of these two tubes, while the perforated wind tube of the wind chest may be used with all the other circles of the same disk.

B.

If t is much less than t', while t' is a multiple of t, the note (t+t')/2 disappears, and the notes t+t' and t are heard.

Disk No. 2 has--

On circle No. 1 12 holes, distances 30°
" " 2 36 " " 10°
" " 3 48 " " 7½°
" " 4 60 " " 6°
" " 5 24 " " t= 5°, t'=25°
" " 6 24 " 6° 24°
" " 7 24 " 7½° 22½°
" " 8 24 " 10° 20°

Circle 8 produces the notes of circles 1 and 2; circle 7, those of 1 and 3; circle 6, those of 1 and 4; and circle 5, the note of circle 1 and of its sixth harmonic.

C.

If the same circular arc is divided into m and n equal parts; that is to say, if mt=nt', we obtain the notes m and n.

Disk No. 3 has--

Distances.
On circle No. 1 24 holes, distances 15°
" " 2 24 " " 15° & 27 holes, 13-1/3°
" " 3 24 " " 15° " 30 " 12°
" " 4 24 " " 15° " 32 " 11-1/4°
" " 5 24 " " 15° " 36 " 10°
" " 6 24 " " 15° " 40 " 9°
" " 7 24 " " 15° " 45 " 8°
" " 8 24 " " 15° " 30, 36, & 48 holes

Circle 1 produces a single note, circle 2 a second, circle 3 a third, circle 4 a fourth, 5 a fifth, 6 a sixth, 7 a seventh, and 8 a perfect chord.

II.

_Experiments to prove that the shocks may proceed from two or several different places to conspire in the formation of a note, provided that the isochronism of the shocks is sufficiently exact, and that the shocks are produced in the same direction_.

Disk No. 4 has--

On circle 1 24 holes.
" " 2 36 "
" " 3 23 "
" " 4 12 at an angular distance of 10° from the holes
of circle 3.
" " 5 12 holes at an ang. dist. of 20° from those of circle 3
" " 6 12 " " " 0° "
" " 7 12 " " " 15° "
" " 8 12 " " " 15° "

1. If from the same side two currents of air at an angular distance of 15° are directed against circle No. 8 of 12 holes, we obtain the octave of the note produced by the same circle if only one current is used.

The wind-chest is provided with a special arrangement for this experiment. By pulling out button 8, we give vent to 12 currents of air spaced like the twelve holes of the disk; on pulling out button 9 we also produce 12 currents, but they are situated just between the first. Each of these two buttons pulled out alone will produce the same note corresponding to 12 holes, but drawn together they produce the octave, or the note of circle 1.

2. If two currents of air are directed against two similar circles whose holes are situated on the same radii, we obtain the same result.

In this experiment, circles 7 and 8 are sounded by pulling out buttons 7 and 9.

3. When two currents of air are directed on the same radius against two circles of similar holes arranged alternately, these circles sounded simultaneously will produce the octave of the note which one of them would give alone.

This experiment is performed by sounding circles 6 and 7 and pulling out buttons 6 and 7.

4. If we direct three currents of air on the same radius against three similar circles having holes alternating by a third of the distance between two holes of the same circle, the three circles together produce the fifth of the octave (Note 3) of a single circle.

Circles 3, 4, and 5 sounded together emit the note of circle 2.

(By sounding only two circles, 3 and 4, or 4 and 5, we make the same experiment with two circles as disk No. 2 enabled us to make with circle 8 alone; also, by sounding circle 3 alone, we obtain the note corresponding to 12 holes; then pulling out button 4, the notes corresponding to 12 and 36 holes are heard suddenly and very strongly; but as soon as circle 5 is sounded also, the note of 12 disappears completely, and we have left only that corresponding to 36 holes.)

III.

_Effects of interference produced by shocks in opposite directions_.

1. If we direct against a circle of holes two currents of air in opposite directions, the note obtained with a single current is very much weakened, if the two currents reach the holes simultaneously. If the impulses are not isochronous, the intensity of the note is increased.

2. If the two currents are directed against two circles of the same number of holes, the effect is the same as for the two preceding cases.

3. If two currents of air are directed against two circles, one of which has twice as many holes as the other, we obtain only the low note if every shock of one is isochronous with every shock of the other.

We obtain the notes of both circles, one of which is the octave of the other, if there is no isochronism between the shocks.

Disk No. 5 has three circles of 36, 36, and 72 holes. The air currents are directed against the circles of holes through the movable tubes, made so that they can be detached at pleasure. All these experiments require great precision in the arrangement of these wind tubes. To make sure that the tubes are simultaneously before two holes of the disk, it is well to put little rods through the holes, reaching into the wind tubes, and to remove them only when the tubes are firmly attached. The experimenter should be careful also to place the two tubes exactly at the same distance from the turning disk. It is clear that notwithstanding all these precautions we never obtain perfect interference, but only the weakening of notes that ought to disappear entirely if all the arrangements were made with mathematical exactness, and also if the ear could have absolutely the same position with regard to impulses produced in opposite directions.

IV.

_Beats_.

Disk No. 6 has--

8 circles of holes to the number of 1, 2, 23, 24, 25, 47, 48, 49.

Circles 3 and 4, 4 and 5, 6 and 7, and 7 and 8 ought to produce as many beats as circle 1 produces simple shocks; and circles 3 and 5, 6 and 8, as many beats as circle 2 produces simple shocks; but we must content ourselves in these experiments with a much less perfect result, for the following reasons: The disk never being rigorously plane, alternately approaches the single wind pipe and recedes from it. No matter how slight this deviation is, every sound given by a single circle is heard with periodical intensities which complicate the phenomenon. This inconvenience could be avoided by placing several wind-pipes around the circle; but while we can extend the period of the holes in two circles (whose difference is 1) around the whole circle by blowing through a single wind tube, we would be compelled to limit it to the distance between two wind tubes, and it would become too short; for, when the disk rotates with a velocity sufficient to produce notes high enough and intense enough, the beats become too numerous to be easily perceived.

Besides these provisions, which sufficiently illustrate the points to which we desire to call especial attention, Koenig also furnishes two more disks.

The seventh contains 8 circles having 48, 54, 60, 64, 72, 80, 90, and 96 holes respectively. The 1st, 3d, 5th, and 8th will produce a perfect chord when the air is admitted through the 11 holes in the wind chest; with one wind tube the entire gamut may be obtained.

Finally the eighth disk contains 8 circles of holes, whose numbers are in the ratio of 1:2:3:4, etc., and which may be used to illustrate harmonics. C. F. K.

* * * * *

THE MOTIONS OF CAMPHOR UPON THE SURFACE OF WATER.

[Footnote: Continued from SUPPLEMENT No. 391, page 6240.]

To have these movements occur in a constant and invariable manner upon the surface of water, and especially upon mercury, it is necessary to take precautions in regard to cleanliness, this being something that we have purposely neglected to mention to our readers. For we wished, through this voluntary omission, to stimulate their sagacity by bringing them face to face with difficulties that they will perhaps have succeeded in overcoming, with causes of error that they will have perceived, and the principal one of which is the want of absolute cleanliness in the water, vessels, and instruments that they may have used for the experiments.

Thus, very probably, they will have more than once seen the camphor remain immovable when placed in vessels in which they had hoped to be able to see it undergo its gyratory and other motions. Their astonishment will have been no less than our own was when we noticed the sudden cessation of the camphor's motions under the influence of vitreous or metallic objects, such as glass rods or tubes, pieces of gold, silver, or copper coin, table knives, etc., dipped into the liquid in which such motions were taking place before the immersion of the objects under consideration.

The instantaneously _sedative_ power of the human fingers, or of a hair, will have, perhaps, reminded them of some sort of sorcery, or of some diabolic art worthy of the great Albert.

As for ourself, we confess that, after repeating the curious experiments of Mr. Dutrochet day after day, and scrupulously following his directions, we have, in the presence of our results, that were exactly identical with his, almost been tempted to believe ourself to be the victim of some occult power, or at least of some optical illusion, the true cause of which remained a mystery to us. Finally, after many fruitless attempts to find a key to the enigma that engaged our attention, the light finally dawned upon us, and then shone straight in our eyes.

In comparing the last results of our experiments with those that we had obtained previously, we saw, for example, that the camphor moved in the test glasses at a level that was notably higher than that at which its gyration took place the day before, or the day before that. And yet we had always used the same vessels, the same water, and particles detached from the same lump of camphor.

To what, then, could be due the difference observed between the two levels at which we had, in the first and last place, seen the camphor execute its movements? In the absence of any answer that was satisfactory, we finally suspected that the difference that we had noticed was ascribable to the fact that, after the numerous washings that the apparatus had been submitted to in having water poured into them to repeat the experiments, they had gradually been freed from impurities of whatever nature they might have been, and which, unbeknown to us, might have soiled their sides.

Starting with this idea, which was as yet a hyphothetical one, we began to wash our hands, glasses, etc., at first with very dilute sulphuric acid, and then with ammonia. Afterward we rinsed them with quantities of water and dried them carefully with white linen rags that had been used for no other purpose; and finally we plunged them again into very clean water. We thus cut the Gordian knot, and were on the right track.

In fact, on again repeating Mr. Dutrochet's experiments, with that minute care as to cleanliness that we had observed to be absolutely necessary, we saw crumble away, one after another, all the pieces of the scaffolding that this master had with so much trouble built up. The camphor moved in all our vessels, of glass or metal, and of every form, at all heights. The immersed bodies, such as glass tubes, table knives, pieces of money, etc., had lost their pretended "sedative effect" on a pretended "activity of the water," and on the vessels that contained it. The so-called phenomenon of habit "transported from physiology into physics," no longer existed.

The likening of the apparatus employed to obtain motions of camphor upon water, with the entirely physiological apparatus by means of which nature effects a circulation of the liquid contained in the internodes of _Chara vulgaris_, had proved a grave error that was to be erased from the science into which it had been introduced by its author with entire good faith. The true cause of _life_ had not then been unveiled, and the new agent designated as _diluo-electricity_ vanished before the very simple and authentic fact that camphor moves rapidly upon the surface of very pure mercury, in which no one would assuredly suppose that that volatile substance could dissolve.

Mr. Dutrochet attaches great importance to the manner in which the water is poured (with or without agitation) into the vessel with which the experiment is performed. The matter is in fact of little or no importance, and to prove this, it is only necessary to employ a test glass (see figure) provided with a lateral tube, A, that terminates in a lower tubulure, B, above which there is a contraction, C. Upon pouring water into the lateral tube until the level reaches D, and placing a particle of camphor on its surface, the camphor will be seen to continually move about, even when the liquid has reached the upper edge of the vessel. To reduce the level to various heights, it is only necessary to revolve the tube in the cork through which it is fitted to the tubulure. In proceeding thus, agitation or _collision_ of the water is avoided; and yet if the test glass is very clean, the camphor will continue to move at every level of the water.

But, some one will doubtless say, how do you explain the stoppage in the motions of the camphor on the surface of water contained in vessels that are not perfectly clean? Before answering this question, let us say in the first place that the cause of the motions under consideration is due to nothing else but the evaporation of this concrete oil--to effluvia that escape from all parts and that exert upon the body whence they emanate a recoiling action exactly like that which manifests itself in an ælopile mounted upon a brasier, or, better yet, in the explosion of a sky-rocket. A portion of these camphory vapors, as well as a small portion of the camphor itself, dissolves in the water and forms upon its surface an oily layer which is at first very slight, but the thickness of which may increase in time until it becomes (especially if the vessel is narrow) a mechanical obstacle to the gyration of the small fragments of camphor that it imprisons, and whose evaporation it prevents. Now, as this layer of volatile oil may and does evaporate, in fact, after a certain length of time, the camphor then resumes its gyratory motions; but there is not the least reason in the world for saying on that account that it "has _habituated_ itself to the cause which had at first influenced it, and that, too, in modifying itself in such a way as to render null the influence of a cause that has not ceased to be present" (Dutrochet, _l.c._., p. 50).

We have been enabled to convince ourself of the existence of this oily layer of camphor when it was of a certain thickness by introducing under the water on which it, had formed, a few drops of sulphuric ether whose sudden evaporation produced sufficient cold to instantaneously congeal the layer in question and thus render it perfectly visible to the eye. The slight layer of greasy matter that habitually lines the sides of vessels from whence no effort has been made to remove it, produces effects exactly like those of the oil of camphor, that is to say, that in measure as it becomes thicker it likewise arrests the motions of the concrete volatile essence.

This is precisely what happens in a test-glass in which we see the camphor in motion become immovable if the level of the water be raised a few centimeters, and, more especially, if it be raised to the upper edge of the apparatus. In its slow ascent the liquid _licks_ up, so to speak, the oily layer that lines the inner surface of the vessel, and this material spreads over the surface of the water and forms thereupon a layer which, in spreading over the bit of camphor itself, prevents its evaporation, and, consequently, its motions. The existence of the layer under consideration cannot be doubted, since it is made to disappear by causing the water to-overflow from the edges of the vessel, and, more easily still, by spreading a piece of filtering paper over the liquid in which the camphor is in a state of rest. As soon as the paper is removed (without the water being touched by the fingers, it should be understood), the camphor resumes its motions and afterward continues them at all levels.

The fingers themselves, provided they are very clean, have no power to stop the gyration. The following experiment, which is easy to repeat, is an unquestionable proof of this.

Wash carefully the middle finger with aqua ammonia, and afterward with plenty of water, and then dip it into a drinking glass in which a fragment of camphor is rapidly moving, and the gyration will not be stopped. But it will be made to stop instantly if the finger in its natural state (that is, covered with the fatty substances that ordinarily soil the fingers, especially in summer) be dipped into this same glass.

_Movements of Camphor upon Mercury_.--In order to study the motions of camphor, mercury possesses, as compared with water, a great advantage, and that is that we can easily assure ourselves of the degree of cleanliness of this metal by means of the condensed breath. The vapory-deposits thereon in a uniform manner if the mercury is perfectly clean, but forms variously shaded and more persistent spots if it is soiled by foreign bodies But it is extremely difficult to clean mercury completely. To do so Mr. Boisgiraud and I take distilled mercury and leave it for a long time in contact with concentrated sulphuric acid, taking care to often shake the mixture. Then, after removing the greater part of the acid, we throw the metal into a vessel containing quick lime in powder, and finally pass it through a filter containing a few holes in its lower part.

Purified by this process, mercury not only permits of the motions of camphor on its surface, but renders visible the traces of the vapors that escape from it, and which resemble small tadpoles with a long tail that are endowed with very great agility. Nothing is more curious than to see the particle of camphor successively ascend and descend the strongly pronounced curves presented by the mercury near the sides of the vessel that contains it. On raising the temperature of the metal slightly, the motions of the camphor on its surface are accelerated, and the same effects occur with water that has been slightly heated.

The experiments that we have just called attention to show what importance slight impurities may have upon certain results. "They prove," says our learned colleague Mr. Daquin, "that there exists upon polished substances an imperceptible coating of those fatty matters which serve to-day to explain Moser's images." We find therein also a manifest proof and a rational explanation of those grave errors into which the presence of these fatty matters, that have hitherto been scarcely suspected, led so clever and so distinguished a scientist as the illustrious discoverer of endosmosis.--_N. Joly, in La Nature_.

* * * * *

CARBONIC ACID IN BEER.

We present a diagram, on exposition at the last Brewers' Convention in Detroit, of the racking device, devised by J. E. Siebel in 1872, and used at that time in the brewery of Messrs. Bartholomae & Roesing, in Chicago. The object of the apparatus is to retain as much carbonic acid in the beer as possible while racking the same off into smaller packages from the storage vats. The importance of this measure is apparent to every one who knows what pains are taken to preserve the presence of this constituent in all the former stages of the brewing process. In the method of racking off which is in present use in most breweries, the beer is forced through a rubber hose from the cask in the store vault to the barrels, kegs, and smaller packages in the fill room. Owing to the excess of pressure in the beer as it enters the keg, it is evident that a large amount of the carbonic acid gas must escape. The escape of carbonic acid during the process of racking off is indeed so large that even a small difference in the pressure of the atmosphere causes a remarkable difference in this respect. It is, therefore, evident that if a larger pressure can be maintained while racking off, a larger amount of carbonic acid gas will remain in the beer. It is true that the racking off will take a little longer time if done under pressure, but this inconvenience is certainly insignificantly small, when compared with the other labors and troubles daily undergone in a brewery, for the sole purpose to preserve in the beer the carbonic acid in that form in which it has been formed during the fermentation, and in which form it has far more refreshing and other valuable properties than in any other form in which it may be subsequently introduced into the beer by artificial means. The apparatus designed in the accompanying cut is calculated to artificially produce a higher pressure of the atmosphere, at least within the keg which is to be filled with beer. For this purpose, the beer from the store cask running through the pipe, B, enters the keg through a hollow copper bung, fitting light into the bung hole by means of a rubber washer. The air contained in the keg, being replaced by the beer, is forced out by means of the hollow copper bung, taking its course through the pipe, inscribed "Glass Gauge," until it is allowed to escape in the standpipe, C, containing a column of water, the height of which designates the pressure within the keg, and a consequently increased retention of carbonic acid gas. If the keg or barrel is filled with beer, the same becomes apparent from the beer showing itself in the glass gauge; then the faucet, B, is closed, the copper bung is lifted out of the bung hole, and the beer contained in the pipe is just sufficient to completely fill the keg, which is then bunged up, while the apparatus is transferred to the next keg. Should the attendant carelessly neglect to close the faucet in proper time, the surplus beer will not necessarily be wasted, but will be collected in the vessel, D, whence it can be drawn off through e.--_Chemical Review_.

* * * * *

ON THE DIFFERENT MODIFICATIONS OF SILVER BROMIDE AND SILVER CHLORIDE.

Hermann W. Vogel has made a comparative study of the properties of silver bromide, obtained by precipitation in an aqueous solution of gelatin, and those of the same compound prepared by precipitation in an alcoholic solution of collodion. In 1874 Stas called attention to six modifications of silver bromide. One of these, granular bromide of silver, obtained by boiling the flocculent precipitate for several days with water, he stated, was the most sensitive to light of all substances known; exposure for two or three seconds to the pale blue flame of a Bunsen burner being sufficient to blacken it. Important as this fact was for photographers it was not applied for years, and it was only in 1878, when, it having been found that silver bromide precipitated in a gelatine solution and boiled for several hours becomes much more sensitive to light, that the remarks of Stas was recalled. Today these observations have become of the greatest importance to practical photography. They have led to the preparation of the silver bromide gelatin emulsion and the silver bromide gelatin plates, which are twenty times more sensitive than the silver iodide collodion plates, and have become indispensable when impressions are to be taken in a dim light.

The extraordinary sensitiveness of silver bromide in gelatin seemed the more remarkable since it was known that silver bromide in collodion is only moderately sensitive. The explanation was sought for in various directions, but as the result of numerous investigations it appears that the chief cause of the difference is the presence of different modifications of silver bromide. From a consideration of the work already done on the subject, Vogel suspected that silver bromide precipitated in an aqueous colloidal liquid would have notably different properties from silver bromide precipitated in an alcoholic colloidal solution. Silver bromide was prepared in many different ways. Emulsions were made in bromide solutions containing gelatin or collodion (the former aqueous, the latter alcoholic), some with the aid of heat, others without. Part of the emulsion was then poured upon plates kept at a moderate temperature and dried. The remainder was boiled or treated with ammonia before being applied to the plates. He also precipitated silver bromide in dilute gelatin or collodion solutions, allowed it to settle completely, washed the precipitate, and mixed it with a new portion of gelatin or collodion before applying it to the plates. Finally he precipitated pure silver bromide, in the absence of all colloids, by means of pure aqueous or alcoholic solutions of bromides and attempted to bring this upon plates, using gelatin or collodion as a cement. The result of all these experiments is that there are essentially two modifications of silver bromide, the one being obtained by precipitation in aqueous, the other in alcoholic solutions. The first, on account of the position of the maximum of sensitiveness for the solar spectrum, he calls blue sensitive, the other, for the same reason, indigo sensitive.

It is of no consequence whether the aqueous or alcoholic solution in which the silver bromide is formed contains gelatin or collodion, or whether the precipitation is effected with excess of bromide or of silver nitrate. It makes no difference whether the solution is hot or cold, or whether the silver bromide is treated with ammonia or whether it is boiled or not. The only necessary condition is that in precipitating indigo sensitive silver bromide the solutions must contain at least 96 per cent of alcohol. From aqueous alcoholic solutions blue sensitive silver bromide is precipitated.

Besides the difference of sensitiveness toward the solar spectrum, these modifications of silver bromide exhibit other characteristic differences in properties which indicate beyond a doubt that they are two essentially different modifications of the same substance. Among these are, 1st. Their unequal divisibility in gelatin or collodion solutions. The indigo sensitive silver bromide cannot be distributed through a gelatin solution, while the blue sensitive modification does so very readily. 2d. Their unequal reducibility; the blue sensitive silver bromide being reduced with much greater difficulty than the indigo sensitive variety. 3d. Their different action toward chemical and physical sensitizers. 4th. Their different action toward photographic developers. 5th. Their different action under the influence of heat. The blue sensitive variety if heated under water has its sensitiveness perceptibly increased, while the other is not changed by such treatment.

A direct transformation of one modification into the other has not yet been accomplished. The effect of the light upon these substances is incipient reduction, and we might hence suppose that the more reducible indigo sensitive variety would be the more sensitive to light. But this is not the case, because it is not chemical reducibility, but the absorption power for light that is of the greatest importance. Now the blue sensitive silver bromide has a greater absorption power than the indigo sensitive variety, and hence its greater sensitiveness. Silver chloride prepared by methods similar to those used in making the two forms of bromides was also found to exist in two modifications. One is designated as ultra violet sensitive, the other as violet sensitive silver chloride.--_Amer. Chem. Jour_.

* * * * *

ANALYSIS OF A SAMPLE OF NEW ZEALAND COAL.

[Footnote: Read before the Society of Public Analysts on the 28th June, 1883.]

By OTTO HEHNER

Some discussion having recently taken place as to the value of New Zealand coal as a fuel, the following results of a somewhat full analysis may be worthy of being placed on record.

The sample to which the results refer consisted of large brownish black lumps, many of which showed woody structure; the fractures were conchyloid, the surface shiny and highly reflecting. It was interspersed with a considerable amount of an amber colored resin. When powdered it appeared chocolate brown. It burned readily, the flame being bright and very smoky. Its ash was light and reddish brown.

It consisted of--

Water (loss at 212° F.) 20.09
Organic and volatile matter 75.19
Ash 4.72
------
100.00

The organic and volatile constituents had the following percentage composition--

Carbon 71.26
Hydrogen 5.62
Oxygen 21.58
Nitrogen 1.06
Sulphur 0.48
------
100.00

The ash was composed of--

Silica 27.26
Alumina 26.48
Oxide of iron 12.98
Lime 20.19
Magnesia 3.42
Sulphuric acid 9.47
Alkalies and loss 0.20
------
100.00

From these figures the composition of the coal itself calculates as under--

Water 20.09
Carbon 53.58
Hydrogen 4.23
Oxygen 16.23
Nitrogen 0.80
Sulphur 0.36
Silica 1.29
Alumina 1.25
Oxide of iron 0.61
Lime 0.95
Magnesia 0.16
Sulphuric acid 0.44
Alkalies 0.01
------
100.00

One ton furnished 8,458 cubic feet of gas and 8 cwt. of coke.

The very high proportion of water contained in the sample is very remarkable. It was so loosely combined, that even at ordinary temperature it gradually escaped, the coal crumbling to small pieces. The large amount as well as the high percentage of oxygen characterize the so called coal as a _lignite_, with which conclusion the physical characters of the sample are in perfect harmony.

The resin to which I have referred has not been further analyzed. It was found to be insoluble in all ordinary menstrua, such as alcohol, ether, carbon disulphide, benzene, or chloroform, and neither attacked by boiling alcoholic potash nor by fusing alkali. On heating it swells up considerably and undergoes decomposition, but does not fuse.

The coal may be valuable as a gas coal and for local consumption, but the large proportions of water and of oxygen militate against its use as a steam producer, only 58 per cent. of it being really combustible.

* * * * *

DETERMINING MANGANESE IN STEEL, CAST IRON, FERRO-MANGANESE, ETC.

By E. RAYMOND.

The method in question is recommended as easy, expeditious, and accurate. It consists in precipitating all the manganese in the state of peroxide, dissolving it in a ferrous solution so as to bring back the manganese to the manganous slate, and determining volumetrically, by means of potassium permanganate, the quantity of ferrous salt which has been converted into ferric. The method of rapidly precipitating manganese peroxide is peculiar. If we act upon cast-iron or steel with nitric acid and potassium chlorate in certain proportions, and boil the mixture, the manganese is completely precipitated in the state of peroxide insoluble in nitric acid, but retaining a small quantity of ferric oxide. Suppose that we have a sample of steel or manganiferous cast-iron containing less than 7 per cent of manganese. Three grammes are treated in a small flask with 40 c. c. of nitric acid, of sp. gr. 1.20, added little by little. The liquid is stirred, and ultimately heated to complete solution. It is withdrawn from the fire, and 15 grammes potassium chlorate are added, and then 20 c. c. of nitric acid at sp. gr. 1.40. It is boiled for about fifteen minutes, until the escape of chlorine ceases; all the manganese is found thrown down as peroxide; hot water is added, the mixture is filtered, and the precipitate washed with boiling water. To dissolve the manganese peroxide thus obtained we measure exactly 50 c. c. of an acid solution of ferrous sulphate, made up with 40 grammes ferrous sulphate to 750 c. c. water and 230 c. c. sulphuric acid (full strength). The 50 c. c. are poured into the flask in which the sample has been dissolved, and to which a little peroxide adheres, and it is then poured upon the precipitate and the filter in a Berlin-ware capsule. The manganese peroxide dissolves very readily, transforming its equivalent of ferrous sulphate into ferric sulphate. The liquid is then diluted to 100 or 150 c. c. for the next operation. We then take a solution of permanganate formed by the same proportions as are used in determining iron by the process of Margueritte (5.65 grammes of the crystalline salt per liter of water), and determine its standard exactly. By means of this liquid we determine volumetrically the quantity of ferrous sulphate remaining in the solution of manganese. We take then 50 c. c. of the original solution of ferrous sulphate diluted as above, and determine the total ferrous salt.

The difference between the two determinations corresponds to the ferrous salt which has been peroxidized by the manganese peroxide. The quantity of iron thus peroxidized multiplied by 0.491 gives the quantity of manganese contained in the portion operated upon. In the case of a steel or cast iron containing but little manganese it is convenient to dissolve the peroxide in 25 c. c. only of the ferrous solution. Small Gay-Lussac burettes may then be used in the titration of only 0.010 meter internal diameter, and graduated into one-twentieth c. c., which allows of great exactitude in the determination. For a spiegeleisen not more than 1 gramme of the sample should be taken, and for a ferro-manganese 0.3 gramme.

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MANGANESE AND ITS USES.

Manganese is one of the heavy metals of which iron may he taken as the representative. It is of a grayish white color, presents a metallic brilliancy, and is capable of a high degree of polish, is so hard as to scratch glass and steel, is non-magnetic, and is only fused at a white heat. As it oxidizes rapidly on exposure to the atmosphere, it should be preserved under naphtha.

It occurs in small quantity in association with iron in meteoric stones; with this exception it is not found native. The metal may be obtained by the reduction of its sesquioxide by carbon at an extreme heat.

Manganese forms no less than six different oxides--viz., protoxide, sesquioxide the red oxide, the binoxide or peroxide, manganic acid, and permanganic acid. The protoxide occurs as olive-green powder, and is obtained by igniting carbonate of manganese in a current of hydrogen. Its salts are colorless, or of a pale rose color, and have a strong tendency to form double salts with the salts of ammonia. The carbonate forms the mineral known as manganese spar. The sulphate is obtained by heating the peroxide with sulphuric acid till there is faint ignition, dissolving the residue in water and crystallizing. It is employed largely in calico printing. The silicate occurs in various minerals.

The sesquioxide is found crystallized in an anhydrous form in braunite, and hydrated in manganite. It is obtained artificially as a black powder by exposing the peroxide to a prolonged heat. When ignited it loses oxygen, and is converted into red oxide. Its salts are isomorphous with those of alumina and sesquioxide of iron. It imparts a violet color to glass, and gives the amethyst its characteristic tint. Its sulphate is a powerful oxidizing agent.

The red oxide corresponds to the black oxide of iron. It occurs native in hausmannite, and may be obtained artificially by igniting the sesquioxide or peroxide in the open air. It is a compound of the two preceding oxides.

The binoxide, or peroxide, is the black manganese of commerce, and the pyrolusite of mineralogists, and is by far the most abundant of the manganese ores. It occurs in a hydrated form in varvicite and wad. Its commercial value depends upon the proportion of chlorine which a given weight of it will liberate when it is heated with hydrochloric acid, the quantity of chlorine being proportional to the excess of oxygen which this oxide contains over that contained in the same weight of protoxide. When mixed with chloride of sodium and sulphuric acid it causes an evolution of chlorine, the other resulting products being sulphate of soda and sulphate of protoxide of manganese. When mixed with acids, it is a valuable oxidizing agent. It is much used for the preparation of oxygen, either by simply heating it, when it yields 12 per cent. of gas, or by heating it with sulphuric acid, when it yields 18 per cent. Besides its many uses in the laboratory, it is employed in the manufacture of glass, porcelain, and kindred wares.

Manganic acid is not known in a free state. Manganate of potash is formed by fusing together hydrated potash and binoxide of manganese. The black mass which results from this operation is soluble in water, to which it communicates a green color, due to the presence of the manganate. From this water the salt is obtained _in vacuo_ in beautiful green crystals. On allowing the solution to stand exposed to the air, it rapidly becomes blue, violet, purple, and finally red, by the gradual conversion of the manganate into the permanganate of potash; and on account of these changes of color the black mass has received the name of mineral chameleon.

Permanganic acid is only known in solution or in a state of combination. Its solution is of a splendid red color, but appears of a dark violet tint when seen by transmitted light. It is obtained by treating a solution of permanganate of baryta with sulphuric acid, when sulphate of baryta falls, and the permanganic acid remains dissolved in the water. Permanganate of potash, which crystallizes in reddish purple prisms, is the most important of its salts. It is largely employed in analytical chemistry, and is the basis of Condy's Disinfectant Fluid.

Manganese is a constituent of many mineral waters, and is found in small quantities in the ash of most vegetables and animal substances. It is always associated with iron.

Various preparations of manganese have been employed in medicine. The sulphate of the protoxide in doses of one or two drachms produces purgative effects, and is supposed to increase the excretion of bile; and in small doses, both this salt and the carbonate have been given with the intention of improving the condition of the blood in cases of anæmia. Manganic acid and permanganate of potash are of great use when applied in lotions (as in Condy's Fluid diluted) to foul and fetid ulcers. In connection with the medicinal applications of manganese it may be mentioned that manganic acid is the agent employed in Dr. Angus Smith's celebrated test for the impurity of the air.

It is the glass maker's soap of glass manufacture, and is used to correct the green color of glass, which is owing to the presence of protoxide of iron. This it converts into the comparatively colorless peroxide.

It is also used in the Bessemer and similar processes, to decompose the oxide of iron. Spiegeleisen, an iron which contains a natural alloy of from 10 to 12 per cent. of manganese, is used for this purpose when conveniently attainable.--_Glassware Reporter_.

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OZOKERITE, OR EARTH-WAX.

By WILLIAM L. LAY.

ON THE DEPOSITS OF EARTH WAX (OZOKERITE) IN EUROPE AND AMERICA.

[Footnote: Abstract from a paper read before the New York Academy of Sciences.]

There exists a large mining and manufacturing industry in Austria, that of ozokerite, or earth-wax, which has nothing like it in any other part of the known world, an industry that supplies Europe with a part of its beeswax, without the aid of the bees. It may not be generally known that the mining of petroleum was a profitable industry in Austria long before it was in this country. In 1852, a druggist near Tarnow distilled the oil and had an exhibit of it in the first World's Fair in London. In America, the first borings were made in 1859. Indeed, the use of petroleum as an illuminator was common at a very early age in the world's history. In Persia at Baku, in India on the Irawada, also in the Crimea, and on the river Kuban in Russia, petroleum has been used in lamps for thousands of years. At Baku the fire worshipers have a never-ceasing flame, which has burned from time immemorial. The mines of ozokerite are located in Austrian Poland, now known as Galicia. Near the city of Drohabich, on the railway line running from Cracow to Lemberg, is a town of six thousand inhabitants, called Borislau, which is entirely supported by the ozokerite industry. It lies at the foot of the Carpathian Mountains. About the year 1862, a shaft was sunk for petroleum at that place. After descending about one hundred and eighty feet, the miners found all the cracks in the clay or rock filled with a brown substance, resembling beeswax. At first, the layers were not thicker than writing paper; but they grew thicker gradually below, until at a depth of three hundred feet they attained a thickness of three or four inches. Upon examination, it was found that a yellow wax could be made of a portion of this substance, and at once a substitute for wax was manufactured.

The discovery caused an excitement like the oil fever of 1865 in America. A large number of leases were made. When I saw the wells of Pennsylvania, in 1879, there were more than two thousand. The owner of the land received one-fourth of the product, and the miners three-fourths. In the petroleum region, the leases at first were whole farms, then they were reduced to 20, then 10, then 5, and at last to 1 acre, which is a square of 209 feet.

But in the ozokerite region of Poland, where everything is done on a small scale, when compared with like enterprises in this country, the leases were on tracts thirty-two feet square. These were so small that the surface was not large enough to contain the earth that had to be raised to sink the shaft; consequently the earth had to be transported to a distance, and, when I saw it, there was a mound sixty or seventy feet high. Its weight had become so great that it caused a sinking of the earth, and endangered the shafts to such an extent that the government ordered its removal to a distance and its deposit on ground that was not undermined. The shafts are four feet square, and the sides are supported by timbers six inches through, which leaves a shaft three feet square. The miner digs the well or shaft just as we dig our water wells, and the dirt and rock are hoisted up in a bucket by a rope and windlass. But one man can work in the shaft at a time. For many years no water was found; but, as there is a deposit of petroleum under the ozokerite, at a depth of six hundred feet from the surface, the miners were troubled with gas. This is got rid of by blowing a current of fresh air from a rotary fan through a pipe extending down the shaft as fast as the curbing of timber is put in place. The ozokerite is embedded in a very stiff blue clay for a depth of several hundred feet; below, it is interlaid with rock. [Specimens of crude and manufactured ozokerite were on exhibition, through the kindness of Dr. J. S. Newberry.]

That part of the earth's surface has more miners' shafts to the acre than any other part of the globe. As wages are very low in Poland, averaging not more than forty cents a day for men and ten cents for children, a very small quantity of ozokerite pays for the working. If thirty or forty pounds a day is obtained, it remunerates the two men and one or two children required to work each lease. When the bucket, containing the earth, rock, and wax, is dumped in the little shed covering the shaft, it is picked over by the children, who detach the wax from the clay or rock with knives. The miners use galvanized wire ropes and wooden buckets. When preparing to descend, they invariably cross themselves and utter a short prayer. The business is not free from danger, carelessness on the part of the boy supplying the fresh air, or the caving in of the unsupported roof, causing a large number of deaths. One of the government inspectors of the mines informed me that in one week there had been eight deaths from accidents.

The ozokerite is taken to a crude furnace, and put into a common cast iron kettle, and melted. This allows the dirt to sink to the bottom, and the ozokerite, freed from all other solids, is skimmed off with a ladle, poured into conical moulds, and allowed to cool, in which form it is sold to the refiners, for about six cents per pound. The quantity produced is uncertain, as the miners take care to understate it, for the reason that the government lays a tax upon all incomes, and the landowner demands his one-fourth of the quantity mined. The best authority is Leo Strippelman, who states the quantity produced in fifteen years at from 375,000,000 to 400,000,000 pounds, worth twenty-four millions of dollars. As the owners of the land get one-fourth of the sum, they received six millions. This is at the rate of four hundred thousand a year, a rather valuable crop from some two hundred acres of land.

The miners do not support the earth by timber or pillars, as they should; the result is that the whole plot of about two hundred acres is gradually sinking, and this will eventually ruin the industry in that part of the deposit. In another part of the same field, a French company has purchased forty acres, and it is mining the whole tract and hoisting through one shaft by steam power. In that shaft they have sunk to a depth of six hundred feet, and are troubled with water and petroleum. These they pump out very much the same way as in coal and other mines, worked in a scientific manner. The thickest layer of ozokerite found is about eighteen inches, and this layer or pocket was a great curiosity. When first removed at the bottom of the shaft, it was found to be so soft that it was shoveled out like putty. During the night it oozed into the space that had been emptied the day before; this continued for weeks, or until the pressure of the gas had become too weak to force it out.

I have been occupied in the petroleum region of Pennsylvania since 1860, have seen all the wonderful development of the oil wells, and was very much interested in contrasting the Austrian ozokerite and petroleum industry with the American. It is a good illustration of the difference between the lower class of Poles and Jews and the Yankee. Borislau, after twenty years' work, was unimproved, dirty, squalid, and brutal. It contained one school house, but no church nor printing office. None of its streets were paved, and, in the main road through the town, the mud came up to the hubs of the wagon wheels for over a mile of its length. In places, plank had to be set up on edge to keep the mud out of the houses, which were lower than the road. It contained numerous shops, where potato whisky was sold to men, women, and children. It depends on a dirty, muddy creek for its supply of water. Its houses were generally one-story, built of logs and mud.

On the other hand, Oil City, a town of the same age and size, contained eight school houses (one a high school building), twelve churches, and two printing offices. It has paved streets, which, in 1863, were as deep with mud as those in Borislau in 1879. It has no whisky shops where women and children can drink. Many of its houses are of brick, two, three, four, and five stories high. Its water works cost one hundred and fifty thousand dollars. All this has been done since 1860, when it did not contain forty houses.

I saw in the market place of Borislau women standing ankle deep in the mud, selling vegetables. One woman really had to build a platform of straw, on which to place a bushel of potatoes; if the straw foundation had not been there, the potatoes would have sunk out of sight. Borislau is three miles from Drohobich, a city of thirty thousand inhabitants; between the two places, in wet weather, the road was impassable. For a third of the way, it was in the bed of the creek; and I had to wait a day for the water to fall so as to navigate it in a wagon. On inquiring why they did not improve the road, I found the same difficulty as the Arkansas settler encountered with his leaky roof; when it rained he could not repair it, and when it was dry it did not need repair: so with the road to Borislau.

Ozokerite (from the Greek words, "Ozein," to smell, and "Keros," wax) is found in Turkistan, east of the Caspian Sea; in the Caucasian Mountains, in Russia; in the Carpathian Mountains, in Austria; in the Apennines, in Italy; in Texas, California, and in the Wahsatch Mountains, in the United States. Commercially, it is not worked anywhere but in Austria; although, I believe, we have in Utah a larger deposit than in any other place. I made two journeys to examine the deposits in the Wahsatch Mountains. For a distance of forty miles, it crops out in many places, and on the Minnie Maud, a stream emptying into the Colorado, I found a stratum of sand rock, from ten to twelve feet thick, filled with ozokerite.