Obrazy na stronie

; } July 28, 1876. Measuring Air in Mines.

37 in reading off the velocity from such the average of the recorded with the linear distance which it had travelled, vibrations must be taken. But with the windmill anemo- the coefficient numbers for correction were deduced. meters the altered speeds are more difficult to detect, and This form for correction M. Combes put into an equation, they are also accompanied by the serious defect that when namely :the intermittence is great the number of revolutions

v == a X n + b. recorded are so largely in excess as to be practically use. less, owing to the momentum which the wheel attains, n being the number of revolutions indicated by the anewhen the current is quick, carrying it (especially when mometer, and a and b are two coefficient constant the wheel is a heavy one) with but slightly lessened speed numbers determined by the series of experiments, and v through the periods when the current is slow.

the true velocity of the air. This formula is still used, This exaggeration of the revolutions of wheel anemo- except that other letters are now more common. meters in intermitting currents may be readily proved, This whirling machine of M. Combes was probably the either by watching the instrument when blown upon in first of the kind. On seeing it, I saw at once that the puffs, or by passing it intermittingly over any given dis- principle was good, but that the mode of carrying it into tance in a still atmosphere. It may also be proved by practice might be improved ; and having described it to placing the instrument in an intermitting current, when Mr. Casartelli, of Manchester, he constructed an improved the actual average velocity can be accurately known, as machine, which was fixed on the floor, and with a whirlin those cases where the total quantity of air passing is ing circle of about 25 feet in circumference, that of M. known by having to pass through an air-pump of certain Combes being much smaller. Improving upon this some dimensions, and making a certain number of strokes per time afterwards, Mr. John Daglish, then viewer at the minute. When furnaces or fans are used as the ventilat. Hetton Colliery, in Durham, in conjunction, I think, with ing power, the intermittence is generally not of much Mr. Lindsay Wood, adapted to a machine, on the same importance, except when air doors are opened and such principle, a weight by which steady velocity was given, like, or when firing up the furnace, or if there be some the speeds being varied according to the increased or irregularity in the construction or working of the fan. decreased weight attached at one time. And this is the But with a single air-pump, worked with one piston, or if whirling machine now used by instrument makers for there be two pumps and two pistons, but changing stroke setting the scale on the quadrant of the Dickinson anemo. at the same time, the effect upon the anemometer, caused meter, and for ascertaining the correction for bringing by the intermitting current, is such that the revolutions revolutions into velocities with the windmill anemometers. are enormously increased. The intermittence is even When, however, a standard anemometer of either kind perceptible, and affects the anemometer when there are has been obtained, it may be used for setting and testing two pumps, one of which changes stroke when the other other anemometers by, provided that the two be carefully is at half stroke, but this greatly lessens the injurious experimented upon together in the same currents of air. effect, and the current is comparatively steady.

Instead of using the formula for deducing the velocity Similarly exaggerated results also occur with the wind. from the revolutions of windmill anemometers, the correcmill anemometers when they are changed about at short tion is now frequently, and indeed more readily, made intervals, as is not uncommon, in endeavouring to get an simply by adding a number, which, by, testing, as preaverage velocity of the current in the various parts of the viously described, is found applicable to the particular space where the observation is being taken. In these instrument at different velocities. Thus, if it requires a instances the momentum attained in the quick part of the current of say 50 feet per minute before the wheel begins current carries the wheel round at a higher velocity to revolve, it would require an addition of that number to than it would have attained in those parts where the ascertain the velocity of the air when the anemometer current is slow.

just begins to move, and so on, varying with the respecInaccuracy in this latter respect may, however, be tive velocities and instruments. For making the correcavoided by having separate anemometers placed at the tion in this way, the numbers to be added are sometimes same time in each part of the airway space where the given in a tabular form, and sometimes in the form of a velocity varies, and averaging the results. When, how diagram, from which the number has to be measured by a ever, only one anemometer is used for measuring a scale. The correction, as before stated, varies with each current which varies at different parts of the space where anemometer ; but with Biram anemometers of like conthe velocity is being taken, the anemometer should either struction, and registering revolutions without any atbe held for a long time in each part of the space, so as to tempted correction in the instrument, the required addition minimise the effect caused by the momentum of the wheel, for correction does not vary much, and it would appear or a separate measurement should be made of the re- that, with instruments so constructed, the correcting spective velocities, and an average taken of the results. number to be added diminishes as the velocity increases, But in this way it will have to be assumed that the the number being often small when the revolutions exceed current continued uniform whilst the respective observa- 400 per minute. The ratio of correction appearing, tions were being taken, which perhaps may not have been generally, like the asymptote of the hyperbola, always the fact.

approaching, but never meeting. The space occupied by the operator's body in using any From these sources of error in the measurement of air anemometer, especially in small airways, or if the instru- currents in mines many mistakes have apparently been ment be not properly faced to the current, may also, made in the amounts of ventilation, and when the result obviously, render the result inaccurate.

has been used for determining the amount of power It is also essential in using windmill anemometers to utilised by ventilating machines, the percentage has been ascertain the proportion existing in each instrument greatly exaggerated. between the number of revolutions and the velocity of the For comparative observations of the ventilation made air-current. In M. Combes's treatise, previously named, from time to time in a mine, the surest way is to place the whirling machine by which he made experiments to the same anemometer on the same spot, and under the find this correction is described. I had an opportunity of same circumstances, on each occasion relying upon reseeing this whirling machine at the instrument maker's volutions and not velocity. (M. Newman, I think) when in Paris, in 1853. It con- But for ascertaining the actual quantity of air passing sisted simply of a balanced rod, on one end of which the in a mine when the current is intermitting-so difficult, anemometer was placed, and being held overhead by one indeed almost insurmountable, is the process with an hand and twirled round on a spindle by the other hand. anemometer—that, where open lights are allowed, it By taking a series of observations at different speeds over seems preferable (although it has been called a barbarous certain linear distances, in a still atmosphere, and com- way) to resort to the old rough and ready ways, by the paring the number of revolutions which the ancmometer' smoke of gunpowder or tobacco, or by the fame of a



Measuring Air in Mines.

{ ,

July 28, 1875. candle, as previously described ; and where gunpowder, 1

NOTICES OF BOOKS. smoking, and open lights are prohibited, a small balloon filled with gas, to float in the air and bound about from roof to floor and side to side, as carried by the air current, Analysts' Annual Note-Book, 1875. Edited by Sidney Wis a good substitute.

Rich. London: Published for the Author. For steady currents, however, there is nothing so good This book, as its title implies, consists of a selection of as an anemometer. The candle cannot be carried with analytical methods which have appeared during the past the average of the whole current, and the smoke of year. The name of the author is given in every case, but powder or tobacco is found to hang where the current is there is, in most instances at least, nothing to indicate slow, making it at times uncertain what portion of the whether the various papers are reprints from scientific arrival should be taken as indicating the average.

journals and from the Transactions of societies, or whether Similarly erroneous computations of the percentage of they have been originally communicated to the "Analysts' power utilised by ventilating machines have likewise been Annual Note-Book.” We cannot help suggesting made, when, in intermitting currents, the pressure of air that in future issues of this note-book the editor would do (which is one factor in the calculation) has been taken by well to conform to the custom of indicating the source as the common inverted glass syphon water-gauge. Not well as the authorship of his extracts. We must likewise withstanding that in nearly all such gauges the tube is insist on the danger of abridging the descriptions of usually contracted at the bend, the water dances up and analytical processes. To take an instance : in MM. down so that it is impossible to read off accurately the Champion and Pellet's method for determining glucose in average distance between the two surfaces.

presence of sugar Mr. Rich tells us to “collect and wash The want of a compensating water-gauge for measuring the suboxide (copper) formed, place the filter, still damp, the pressure of intermitting currents first presented itself in a capsule, and add dilute hydrochloric acid, which conto me in the year 1861, when measuring the amount of

verts the suboxide of copper into sub-chloride. The power utilised by the Struvé air pumps. On that occa- liquid becomes coloured and the copper passes into the sion, finding it impossible to obtain any reliable measure state of bichloride of copper of a greenish yellow colour of the average pressure of air by the ordinary water-gauge, when it is titrated with chloride of tin.” But if we refer my colleagues, Mr. Thomas Evans and the late Mr. John to the Comptes Rendus, No. 3, Jan. 18, 1875, or, in default, Job Atkinson, and myself, used two ordinary buckets of the Chemical News, vol. xxxi., p. 84, we shall find that water, one bucket being placed outside and the other in the liquid in question is to be * raised to a boil, adding the return air, the water in each being connected by an

by degrees some crystals of chlorate of potash,' by the india-rubber tube. This method served the purpose, but action of which the conversion of the sub-chloride of as the buckets widened towards the top, the area of the copper into the bichloride is eftected. If, as we doubt not, surface of water in each was not equal, and consequently Mr. Rich wishes to render his note-book really useful to the depression of water in one did not correspond exactly analysts, he will agree with us that every step in a novel with the elevation in the other, which made it requisite to analytical method should be fully described. measure the height it rose in one and the depth it fell in

A great part of the matter given relates to the adulterathe other, and to add the two together in order to obtain tion of food and drugs, and must have already come under the total pressure. A readier mode than the buckets of the notice of the majority of chemists in this country. water, as might be expected, soon occurred to us, and in the fact that certain impure ammonia turns a “gooseberry the same year I had a proper compensating water-gauge, red colour" on admixture with nitric acid is not a recent made by Mr. Casartelli, of Manchester, (the one observation. To our certain knowledge it was utilised as shown to the meeting) by which, no matter how inter- a test in dye-works, &c., in the North of England eight mitting the current, an accurate measure of the pressure years ago. may be readily taken, by having the two limbs for the water so large and the connecting aperture at the bottom so small that the flow of water does not sensibly affect Seventh Annual Report of the State Board of Health of the level during the pulsations. The gauge consists of a

Massachusetts; January, 1876. Boston: Wright and brass box, divided by a thin partition into two chambers,

Potter. with glass front, and with the aperture at the bottom We have here a most elaborate report on the sanitary connecting the water in the two chambers regulated by a condition of the State of Massachusetts. The condition tap. The full size of the gauge is 6 inches high, 4 inches of the rivers, the sources of pollution, the water supply broad, and 3 inches wide; the 4 inches in breadth being for domestic and manufacturing uses, the sewerage of the divided by the partition, making the two chambers each towns and villages, and the disposal of the sewage are 2 by 3 by 6 inches. The tap for regulating the flow of all fully described. water between the two chambers is worked outside, under. On the subject of the “Disposal of Sewage” there is a neath the bottom of the gauge. At the top of one of the special paper by Dr. C. F. Folsom, in which the past chambers there is an opening 1 inch in area to admit the experience of the principal European countries is described. pressure of air on that side, and at the top of the other such a treatise would have been exceedingly useful had chamber there is a brass nozzle for inserting through an the author taken the trouble to ascertain the truth. Inaugur hole to admit the pressure of air at the other side. stead of so doing he accepts and retails a number of the There is also a tap on this nozzle for closing when re- statements which English sewage irrigationists have quired. At each side of the glass front, and also down repeated till they believe them. As an instance of the the middle of it in front of the partition dividing the two glaring errors with which this essay abounds we turn to chambers, there are scales graduated into inches and the account of the sewage treatment at Leeds. We are tenths, so that the difference between the level of the told that the authorities there tried several of the precipi. water in the two chambers may be accurately seen. Mr. tating processes one after the other, “finding them all Atkinson soon afterwards had also a gauge of the same failures." This is incorrect ; two, if not three, of the kind made for himself, but his had a pipe which came processes tried have been found successful, and one of outside for connecting the two chambers at the bottom, these has been selected as most completely answering all instead of a tap regulating the size of a hole in the par- the conditions required of a sewage process. The deposit tition, as in mine. "These two compensating water-gauges is not, as Dr. Folsom has been informed, “quite offenwere probably the first of the kind used in this country; sive” whilst drying. The tanks are not made of iron, but on asterwards using them in testing some of the but of masonry; they are not six in number, but twelve ventilating machines in Belgium, we were informed that they are not cleaned out when the deposit becomes a similar gauges had been previously used by the ingenious foot deep-which is never the case in those farthest from mining engineers in that country.

the infall-but pro re nata. The effluent when the opera.


July 28, 1876.
Organisation among Chemists.

39 tion is fairly worked does not “soon putrefy.” The Mn203, &c., which he oughž to be able to answer himself. manure, instead of being unable to find a sale at two I have already given him a capital reference and regret to shillings a ton, is contracted for a twelvemonth in ad- find that he cannot, or will not, avail himself of it. But vance at twelve. What confidence can be placed in an perhaps I had better reply to his questions, though I am author who heaps up inaccuracy upon inaccuracy in such afraid that will not help him much. a manner, and what must we think of his informants ? 1. How does Dr. Phipson know that the 6'20 per cent One truthful confession, however, somewhat redeems this . of Mn203 was not made up of 3'41 MnO2 and 2.79 Mno? imaginative description of the Leeds Sewage Works. Answer.-Because there is no MnO in the sample. The author admits the absence of offensive smell. Here 2. If he does not know how, &c. ? he contradicts one of the most preposterous assertions of Answer.-He does know. the Rivers’ Pollution Commission that "bad smells are 3. What process was employed for the determination of always perceptible.” What he admits further negatives the main quantity of MnO2, and would not that amount another of their baseless statements, that “the process include the 3'41 per cent assuming the latter to have any produces no clearer water than what would have resulted existence ? if tha sewage were allowed to settle by itself.” It so Answer.--No"main quantity" of MnO2 was determined. happens that this point has been experimentally decided 4. If the result of the determination of MnO2 72'17 per at Leeds. Some years ago, we do not know whether, in cent represents the total quantity of that oxide present, consequence of the assertion quoted by Dr. Folsom-a must not the remainder of the Mn necessarily have existed tank at the Old Works was filled with sewage and allowed as MnO and not as Mn203? to settle. The result was not a clear, colourless, inodor- Answer.-Certainly not (vide answer to question 1). ous liquid like that attainable by precipitation, but a 5. If the last question is answered in the affirmative has nuisance which no one could approach without feeling not Dr. Phipson counted his oxygen twice over ? nauseated.

Answer.-It is not answered in the affirmative. Speaking of Leamington the author declares that "in I am, &c., 1870 the authorities of this town, having proved the pre

T. L. Phipson, Ph.D. cipitation processes to be costly and expensive failures, London, July 22, 1876. gave up their tanks and made a contract to deliver their PS.-In my last letter the word “discovered" was sewage upon Heathcote Farm belonging to the Earl of erroneously inserted for determined." Warwick." The only processes which we have ever heard of as having been used at Leamington were the “lime” and the " A B C.” The latter of these was not

PRIZE FOR HARDENING PLASTER CASTS. tried until after the contract had been made with Lord Warwick. Consequently it was a mere interim arrangement and not a “costly and expensive” failure which

To the Editor of the Chemical News. drove the Leamington authorities to irrigation.

Sir,-Will you kindly inform me if the German prize for It is not too much to say that every part of Dr. Fol. a method of preserving plaster casts has been awarded ? som's treatise teems with errors. His notice of sewage | The consignments were to liave been in ty January last, irrigation is as one-sidely favourable, as his remarks on

but I have not been able to obtain any information about precipitation processes are unjustly condemnatory. No the matter. I am, &c., mention is made of the important results obtained by Mr.

D. D. REDMOND, Smee, jun., who showed that milk and butter obtained July 24, 1876. from cows fed on sewage grass became more rapidly offensive than that of cows fed upon normal herbage. No notice is taken of the important evidence of Mr. ORGANISATION AMONG CHEMISTS. Markham that irrigation, even with common river water and appiied only when necessitated by dry weather,

To the Editor of the Chemical News. injures the health of the surrounding districts in India. No less has Dr. Folsom left out of account the valuable Sir, -The formation of an Institute of Professional report of M. Lefeldt, the Prussian commissioner, who

Chemists has undoubtedly been mooted mainly for the complains of the “ mephitic odours"

purpose of raising the status of the chemists; but some

on the model sewage of the proposed regulations in the scheme put forward by farm, and who found the stems of grass from irrigated Mr. Pettengill's clients in the CHEMICAL News of the meadows full of unassimilated sewage matters. Irriga- gth ult., do not by any means appear likely to further this tion is doubtless valuable in climates where there is no rain during half the year, but in England where the bership if he had practised on his own account in the

end. For instance, a person would be eligible for memaverage supply of moisture is too great for our most profession of a consulting or analytical chemist.”, valuable crops it is a delusion which it will puzzle posterity to account for.

This would obviously admit all those quacks who have' In short, we must pronounce Dr. Folsom's treatise an

chosen to dub themselves " Analytical and Consulting utterly untrustworthy compilation, and for the sake of while at the same time many of the so-called " works'

Chemists” without the faintest qualification for the work, sanitary science in America we regret that it has ever appeared.

chemists” who have had a thoroughly good scientific The other portions of the volume are of much greater would, unless they had advertised themselves as

training with much experience in technological work, value.

Analytical and Consulting Chemists,” be excluded.

For the purpose of guiding in its action towards the proposed Institute, I am instructed by the Council of the

Faraday Club (which consists solely of chemists of this CORRESPONDENCE.

district) to ask publicly of those engaged in forwarding the new scheme :

1. How are “high” and “low" analysts and quacks ANALYSES OF MANGANESE OXIDES.

in general now in practice to be excluded?

2. How will technology be represented on the Board of To the Editor of the Chemical News.

the proposed Institute ?-I am, &c., SIR, -I notice in the CHEMICAL News (vol. xxxiv., p. 30)

Pro the Council of the Faraday Club, that Mr. Alfred Allen has been asking me some more

GEORGE E. Davis (Hon. Sec.). questions with regard to the determination of MnO2, Runcorn, July 21, 1876.


Chemical Notices from Foreign Sources. { ,

July 28, 1876. CHEMICAL NOTICES FROM FOREIGN the Department of l'Herault, as pointed out by N. Thomas SOURCES.

(Comptes Rendus, May 8).

Influence of Temperature upon Magnetisation.

M. J. M. Gaugain.-Not adapted for abstraction. Note.-All degrees of temperature are Centigrade, unless otherwise expressed.

Extension of the Principle of Carnot to the Theory

of Electrical Phenomena : General Differential Comptes Rendus Hebdomadaires des Seances, de l'Acadenie Equations of Equilibrium and of the Movement of des Sciences. No. 25, June 19, 1876.

any Reversible Electric System whatsoever.-M. Cause of the Movements in the Radiometer of G. Lippmann.-A mathematical paper, incapable of useful Mr. Crookes.-M. Govi.-Fresnel had found, in 1825, abstraction. that light bodies freely suspended in an ordinary vacuum Differential Actinometer.- M. N. Egoroff. — The might perform under the action of light or heat certain author describes his apparatus, with which he hopes to movements, which he referred to the thermic currents of determine the coefficients of absorption of the ultra-violet the rarefied gas contained in the receiver. These same rays. movements, obtained in a far more perfect vacuum, have

Researches on the Commercial Analysis of Raw been lately ascribed by Mr. Crookes to the impulsive force Sugars.-A. Riche and Ch. Bardy.—The chief novelty in of the luminous rays. It is little probable that the dis- the authors' method is that they take a sample five times placement of a gas the pressure of which is reduced to a

larger than usual, and operate upon one-fifth of the solufew hundredths of a m.m. can impress an appreciable mo- tion, in order thus to obtain a fairly representative sample. tion on bodies whose mass is always relatively very large. They also employ a modification of the ordinary polariAs for the impulsive force of light, it ought to be nil if it

metric tube. be true that light and heat are merely vibratory movements of the ether or of the ultimate particles of bodies. It is

New Class of Colouring Matters.-M. Ch. Lauth.no more possible for light to drive a body before it than Reserved for insertion in full. for the sounds of a musical instrument to sweep along a Certain Derivatives of Isoxylene.-M. Ch. Gundefeather or a particle of dust in the direction in which they lach. This paper contains an account of the chloride of are propagated. If the impulsive force of light were isotolyl and of isotoluic aldehyd. proved, it would be necessary to renounce the theory of The Nickel Ore of New Caledonia, or Garnierite. Huyghens; but before doing that we must at least exhaust

-M. J. Garnier.—The nickel ores of New Caledonia are all possible means of explaining the movements studied by, not arsenio-sulphides like those hitherto utilised, but siliFresnel and by Mr. Crookes. If the thermic currents of

cates of nickel and magnesia. The ore is found amidst rarefied gases contained in the receiver where the move.

the masses of serpentine very abundant in certain parts of ment is produced do not suffice for the explanation of the

the island, and associated with euphotides, diorites, am. faas observed, there is another cause of displacement phibolites, &c. The nickel is accompanied by iron, chrome, much more efficacious, but hitherto not taken into account, and cobalt; these metals, especially the two former, are which may well give the true explanation of the pheno- of an unexampled abundance. The cobalt is associated

This cause is merely the dilation by heat, or the with manganese. contraction by cold, of the gaseous layers which all bodies retain on their surface, even when placed in an absolute

On Nitro-Alizarin.-M. A. Rosenstiehl.-The author vacuum. The mass of these gaseous strata is far from demanded the opening of a sealed paper deposited by him being insignificant relatively to that of the bodies which on March 13, 1876, and containing an account of the new retain them, especially when they are in a very fine state compound. Madder-red exposed to nitrous vapours beof division, like lamp-black, platinum-black, &c.; or if they comes orange, and the shade thus produced is only renare endowed with an especial affinity for certain gases, as

dered more brilliant by washing and by boiling soap-lyes. palladium for hydrogen. If we admit that this is the true Turkey.red undergoes the same change, the resulting explanation of the facts studied by Mr. Crookes, we may colour being quite as solid as that from which it is derived, construct insensible radiometers by heating the immovable and of a tone and a brightness which could hitherto only discs of the apparatus during the action of the mercurial be produced on printed goods by means of chromate of pump. So long as we have not removed from the apparatus lead. The orange obtained by the action of nitrous vapours the source of movement just pointed out, it is needless to

is so much the brighter, as the madder-red contains less have recourse for the explanation of the phenomena to an purpurin. The colour can scarcely be withdrawn from impulsive force, which would be at variance with all that the fibre upon which it is deposited without attacking the we know best concerning the nature of light. M. Fizeau latter. The small quantity obtained dyed an orange shade gave an account of an experiment which does not seem

with mordants of alumina. Nitrous vapour brought in favourable to the explanation given by Govi. If a series contact with alizarin in solution, or suspended in water, of equidistant candles are placed around a radiometer, acetic acid, alcohol, sulphuric acid, &c., produced comforming a circle of about 50 centimetres in diameter, in the pounds of a yellow colour, but devoid of tinctorial power. centre of which is the instrument, it is equally and symme- This result agrees with that of Ntenhaus, who found that trically illuminated all around its axis of rotation, so that alizarin was reduced by nitrous acid to anthraquinon under the discs whilst turning receive constantly the same quan circumstances very analogous. Fuming nitric acid emtity of light as well on their blackened as on their polished ployed alone, or mixed with sulphuric acid, did not give a surfaces. The rotatory movement being established, satisfactory result. The author then prepared the new under these conditions, with a speed of about ten revolu- colour by pouring the commercial alizarin paste into large tions in seven seconds, the number of rotations was care- glass flasks, coating the interior therewith by means of fally taken in each successive five minutes. The speed agitation, draining, and drying, thus leaving the flasks was found constant, and did not slacken during an entire lined with a layer of finely divided alizarin. They were hour. In these conditions would not the speed of the then filled with nitrous vapours and stoppered, when in a rotation diminish and cease at the expiration of a very few minutes the colour of the alizarin was changed, and short time it it was really produced by the liberation of the gas decolourised. Two colouring matters were formed, condensed gases or vapours from the blackened surfaces ? one of which, probably unchanged alizarin, gave a red We cannot from the uniformity of the illumination admit with aluminous mordants, whilst the new substance dyed the supposed alternations of condensation and emissions an orange. The new colour is composed ofnecessary for the continued maintenance of the movement.


58.94 Existence of Mercury in the Cevennes.-M. Ley.


2'45 nerie.-The author confirms the existence of mercury in








220 traces

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IO 20

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,} Chemical Notices from Foreign Sources.

41 July 28, 1876. answering to the formula C14H7(NO2)04. By the reduc- salt is decomposed. This solution is made by dissolving tion of nitralizarin the author has obtained two products, 6.6 grms, in the same manner as the foregoing, and the which are formed successively : the one dissolves in alka- binoxide of nitrogen is collected in a second graduated lies with a blue colour, and dyes a garnet with aluminous jar. The two jars are kept till they have acquired the mordants ; the other dissolves in alkalies with a brown same temperature and the respective volumes of gas procolour, and dyes a catechu colour with alumina.

duced are read off, care being taken to keep them immersed

so that the water may stand at the same level within and Bulletin de la Societe Chimique de Paris,

without. The volume of gas produced by a given weight No. 1, July 5, 1876.

being thus known, the proportion of real nitre existing in

the sample under examination is readily calculated. On Benzylic Naphthalin.-M. Pierre Miguel.-Not suitable for abstraction.

(In a subsequent part of the paper the author speaks of

the determination of nitrogen by the “procede WinckMetallurgy of Silver in the Moist Way.--M. An. ling." On careful examination this proves to be a tony Guyard (Hugo Tamm).—This paper

devoted to Gallicised version of the name of Mr. Wanklyn.) the treatment of the sulpho-antimoniuretted ores of Bolivia, known as Rossicler,--very rich, but so difficult to of the Addition of Hypochlorous Acid.-M. L. Henry.

On Isobutylenic Chlorhydrine, and on the Law treat in the dry way that many smelters refuse to work ---Already noticed. them. They may, however, be very advantageously treated in the moist way, the sole condition of success

On the Law of Dulong and Petit.-M. A. Terreil. being the use of a quantity of acid sufficient to oxidise

- Already noticed. the sulphur and all the metals. The following analyses On Erythrophlæum Guineense and couminga.show the general composition of these ores :

MM. N. Gallois and E. Hardy.-A chemico-pharma.

ceutical paper, not adapted for abstraction. Sulphur

16:20 17.85

On Certain Derivatives of Isoxylene. — M. Ch. Silver 48:15 46:10 38:10

Gundelach.--Already noticed. Antimony


7'10 Iron

770 0'95

Justus Liebig's Annalen der Chemie,
4:50 4'10 5'25

Band 181, Heft 3.

Combination of the Elements of the Nitrogen traces

1950 Arsenic

Group with the Radicals of the Aromatic Series : 0*15

0-25 Copper

Section I.; on Aromatic Phosphorus Compounds. 0'25

-A. Michælis.-A treatise extending to one hundred pages, Chlorine

0:15 Gangue


and utterly incapable of useful abstraction. 750

On Ammonium Compounds.-W. Lossen.-Like

wise not adapted for abstraction. Analysis of the Peroxide of Manganese.—Dr. T.

On Benzhydroxamic-ethylester. – Dr. Martin E. L. Phipson.—Already noticed.

Waldstein.— The author describes the properties of this Memoir on the Determination of Nitrates.-M. compound, to which he assigns the formulaFerd. Jean.-For the analysis of commercial samples of and its silver salt, and then discusses its constitution,

N(C2H50)(C2H5)HO, nitre the author recommends the following procedure :Into a small glass fiask, holding about 200 c.c., introduce acid, and the benz-hydroxamates ; the decomposition of

with those of ethyl-benz-hydroxamic acid, benz-hydroxamic a concentrated and very acid solution of ferrous chloride, benz-hydroxamic-ethylester by hydrochloric acid, and its The fask is closed with an india-rubber stopper pierced methyl compound. with a hole, through which pass a delivery tube under a leaden shelf in a tank of water lined with lead, and a

Occurrence of Arsenic in An ent Bronzes.-H. very short tube, to which is fixed a small funnel by means Spirgatis.-The author has found arsenic in old Prussian of a flexible caoutchouc tube, the communication with bronzes to the extent of 3.52 per cent. the flask being intercepted by means of a Mohr's springclip or a small glass tap. The trough being filled with water, the ferrous chloride is raised to a boil, and, as soon as the sound made by the condensation of the acid on the

PATENTS. water of the trough announces that' a vacuum has been made in the flask, a gas-jar filled with water is placed ABRIDGMENTS OF PROVISIONAL AND COMPLETE over the opening in the shelf. The jar should be of the

SPECIFICATIONS. capacity of 200 c.c., graduated in tenths. Then we pour House, Widnes, Lancaster. March 11, 1875. - No: 906. This inven:

Improvements in the manufacture of chlorine. H. Deacon, Appleton into the funnel 5 c.c. of a solution of nitrate of soda, tion consists in using a mixture of common salt or other similar formed by dissolving in a litre of 66 grms. of pure nitrate chloride with a compound or salt of copper, or with other so-called of soda recently melted at a low temperature. The solu- chemically active salt, wuch as is now employed in what is known as tion of ferrous chloride being kept at a boil, the solution Deacon's process for making chlorine from hydrochloric acid gas and of nitre is allowed to enter the flask drop by drop, taking source of hydrochloric acid gas, which may be from the well-known

air, previously mixed and heated in combination with a separate care not to empty the funnel completely: 2 to 3 c.c. of manufacture of sulphate of soda by reacting on common salt with sul. distilled water are then placed in the funnel and allowed phuric acid, or otherwise obtained. The common salt used in carrying to enter the funnel, and finally the funnel and the tube with a solution of the so-called chemically active salt or salts, which

out this invention may be in grains, which may either be moistened are rinsed with 5 to 10 c.c. of fuming hydrochloric acid. may, for example, be sulphate of copper; or the common salt and The binoxide of nitrogen produced by the decomposition sulphate of copper may be in solution, and this solution may be used of the nitrate of soda enters the graduated jar, and as

to impregnate pieces of burnt clay or other porous materials there

with, the mixture or impregnated material being subsequently dried. soon as the sound announcing the presence of a vacuum Or salt mixed with copper ore-such, for example, as the sulphurets in the flask is heard the graduated jar is withdrawn and or the oxides--or with other natural or artificially produced insoluble allowed to stand on a support in the trough. This first compounds of coppe:, may, in a fine state of division, be employed in operation makes known the volume of gas obtained from

lieu thereof, or in conjunction with the soluble salts of copper before

referred to. The apparatus, in which the mixtures as described may a known weight of nitre, without it being needful to take be used in combination with a separate source of hydrochloric acid, account of the corrections for temperature, pressure, &c.

may be a column or tower, or a oumber of columns or towers connected Into the flask are then introduced 5 c.c. of a solution of together, and made of iron or brickwork or both,

as more fully de.

scribed in the Specification of a Patent granted to me on September the nitre in question in 100 c.c. of distilled water, and the 13, 1870, No. 2469. During the manufacture of chlorine by this ia


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