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CHEMICAL News,

Atomicity as a Principle of Classification. August 4, 1876.

47 certain manner; they have sought to establish between Here are then three bodies which are derived regularly the atoms that compose them precise ties, admitting the one from the other and in which nitrogen plays a especially that, not only heterogeneous atoms exhaust different part. It is pentatomic in nitrobenzin; triatomic among themselves their disposable atomicities, but that or diatomic, at pleasure, in azoxybenzol; triatomic in these latter may be interchanged between atoms of the hydrazobenzol. It is impossible in any natural classifica. same nature. These hypotheses, which are satisfactory tion to separate chlorine, bromine, and iodine ; but whilst enough when we are treating of saturated bodies, become the two first are monatomic, iodine is decidedly triatomic insufficient when we seek to apply them to incomplete in the compound, IC1z; and it is the same in the tribodies. To remove these difficulties it has been proposed acetate of iodine of M. Schützenberger :to substitute, for absolute atomicity of the elements, ad.

(C2H50) mitted in the outset by M. Kekulé, first, the principle of successive saturation of the atomicities of one and the same atom, the free atomicities of a polyatomic element The same difficulties exist with metals. Let us consider being necessarily either even or odd; then the principle of at first the metals reputed as diatomic-mercury, for relative atomicities, the atomicity of an element depending example. on the nature of the body with which it is combined. But It may be asked, first, What is its atomic weight; these new hypotheses, as M. Berthelot judiciously remarks, second, What is its atomicity? To determine its atomic render the whole atomic theory illusory and bring it back weights we found upon its vapour-density and on the law at last to the law of multiple proportions. However this of Dulong and Petit. Experiment shows that the density of may be, the atomicity of elements is become in the hands mercury is equal to 6'97, whence we deduce for its atomic of atomists a fundamental principle of classification, not weight with reference to hydrogen :only for grouping simple bodies in natural families, but

6997 even for differentiating mineral and organic bodies. Let us take an example : hydrazobenzol and diphenylen

O'0693 diamin are isomeric. We admit that in the former of On the other hand, according to the consideration of these compounds the two atoms of nitrogen, which are specific heats, its atomic weight is equal to 200— not saturated, exchange between themselves their dis. posable atomicities :

64 CoHs-N-H

0'0324 1

It has been sought to explain this anomaly by saying that C6H5-N-H.

the atom of mercury occupies two volumes, a supposition In diphenylen-diamin the nitrogen is saturated and the inadmissible, for it constitutes a true begging the ques. two phenylen groups exchange between themselves their tion. To remove this difficulty there is only, as it seems two free atomicities :

to me in the present state of science, one plausible exC6H4-N2H,

planation, that is, to admit that atomic weight may vary

according to the physical state of the bodies; for mercury C6H4-N2H2.

in the solid as in the liquid state the vibrating mass is

equal to 200; in the gaseous state it is equal to 100. But In my opinion the atomicity of the elements can only be what becomes then of the invariability of the atomic admitted without question when treating of a definite weights ? specific property, as it belongs to atoms, but it is easy to Second, mercury forms with chlorine two compounds, demonstrate that there is nothing of the sort. Phos. We admit that it is diatomic in sublimate. phorus combines at most with three atoms of hydrogen ; it is then here triatomic, but it is pentatomic in contact

HgCl2=Hg" (Cl with chlorine, because there exists a perchloride, PCls; with iodine it forms an iodide, PI2, which corresponds to To preserve for it the same atomicity in calomel it ha no known chloride, &c.

been assumed that this latter compound has for its Nitrogen is monatomic in the protoxide of nitrogen, formula : N20, as in the hyponitrite of silver of Mr. Divers :

CI
N

Messrs. Deville and Troost have found that the density of It is triatomic in ammonia, pentatomic in chlorhydrate of calomel is 8-2 and as there is no dissociation, according ammonia, in cyanuric acid, &c. Nitrobenzine gives suc

to M. Debray, we have for its molecular weight referre cessively by reduction, before yielding aniline, azoxy

to two volumes, hydrogen being taken as unity-
benzol, and hydrazobenzol :-
Nitrobenzin,

O'0692
C6Hg (NO2)
C6H5-N

On the other hand,

1> Azoxybenzol C6H3-N

= Hydrazobenzol, NH-NH

The formula of calomel is then HgCl, a compound in whic

mercury is monoatomic. Mercury is therefore sometimes C6H-NH.

monoatomic, sometimes diatomic in contact with chlorine,

which amounts to saying purely and simply that it obeys We admit that in the first of these compounds nitrogen is the law of multiple proportion when it forms several compentatomic, whilst it is only triatomic in two others; but, pounds with the same element. The difficulties are still what shows, as we may say in passing, how subtle and greater when we consider the polyatomic metals, such as arbitrary are these distinctions is that we may, with quite iron and manganese. Manganese is monoatomic in peras much probability, maintain that nitrogen is only manganic acid ; diatomic in protoxide of manganese ; diatomic in azoxybenzol, in accordance with the following diatomic or tetratomic in pyrolusite; tetratomic in fluoformula :

manganic acid ; hexatomic in the manner of ferricum in C6H5-N.

braunite ; probably heptatomic in the perchloride of M. C6H3-N>0=C6H5-N-0-N-C6H5.

Dumas, &c. According to the preceding considerations N-C.HS

it appears to me doubtful whether the atomicity of

HgCl2= (Hg-Hg)" {CM

Ag}o

8.2x2 =236

Hg=200} =23545

-.

48

Mineral Phosphates and Superphosphate of Lime.

CHEMICAL News,

August 4, 1876. elements can serve for a principle of classification, guished from the atomicity of elements or the atomicity whether for simple bodies or for compounds.

of addition which is contestable. Finally, it becomes in But the word atomicity has been employed in another the hands of chemists a powerful means of classification, and perfectly legitimate sense as representing the relative since it allows us to distinguish simple functions: first, value of molecules among themselves. Thus understood, repeated functions ; second, mixed functions. But the this notion becomes an important principle of classifica- notion of function ought, in the present state of science, tion, on which it is proper to insist. In 1838, Graham to be regarded as the basis of every system of chemical showed that in neutral phosphate of potassium there are classification. three atoms of potassium, and that the acid phosphates differ from this salt only because they contain atoms of hydrogen instead of atoms of potassium. We may re

MINERAL PHOSPHATES AND SUPERPHOS. mark that it is impossible to divide by 3 the atoms of oxygen in neutral salts, and that, accordingly, these latter

PHATE OF LIME.* contain probably in their molecules three times more

By WALTER C. REID. potassium than, e.g., nitrate of potassium. We may make an analogous remark concerning the citrates, which The rapid development of the manufacture of artificial are tribasic; for if the atoms of carbon are divisible by 3, it is not the same with the atoms of oxygen and of manures, and the total inadequacy of bones and bone. hydrogen. In the year 1838, Liebig insisted on the ashes to meet alone the requirements of this trade, have necessity of regarding as polybasic the cyanuric, melonic, caused the consumption of mineral phosphates to increase comenic, citric, aconitic and aconic, tartaric, malic, and of late years to an enormous extent; and it is of im. fumaric acids. Other proofs came to the support of this portance for manufacturers, and others who buy and sell, view, which is now adopted by all chemists. It is thus materials, and the influence of the several constituents of

to know the composition of the raw and manufactured that phosphoric ether contains in the same volume three times as much carbon as nitric ether; and this circum- the former upon the production of the latter. stance is decisive, for it shows that the existence of of all manure works is superphosphate of lime, and in

The basis of nearly all fertilisers and the staple product polybasic molecules is in perfect agreement with the gaseous densities of the ethers. We are thus led with producing it much depends upon the care and attention M. Berthelot to consider the molecule of a bibasic acid as

given to the selecting of the raw materials, as well as to resulting from the fusion of two monobasic intimately preparing and dissolving them, for, simple as the process united. These notions on the acids at first defined in appears, if these are neglected an article quite unfit for mineral chemistry find their application in organic

use is almost certain to be the result. chemistry, which permits us to deduce from them im characteristics, in physical appearance and in chemical

Deposits of raw phosphatic materials having different portant rules of classification. Let us cite an example. Formerly we expressed formic acid and oxalic acid by composition, as well as in the results obtained from them, formulæ containing the same quantity of carbon ; but have been found in nearly every part of the globe. The whilst the former only gives with bases a single series of commercial value of these is chiefly regulated by the perneutral salts, the second furnishes likewise acid salts and centage of tribasic phosphate of lime they contain. The double salts, which is explained in a most natural manner (cæteris paribus) for the manufa&ure of superphosphates:

richer they are in this element the more valuable they are much of carbon as the formic molecule. On the other But the amount of phosphate of lime in a mineral cannot hand, experience shows that whilst a litre of formic ether be taken as the only criterion of its value, for it sometimes contains the carbon of a litre of alcoholic vapour,

oxalic happens that a phosphate containing a lower percentage ether contains in the same volume the carbon of two litres of this ingredient will make a stronger and better superof vapour of alcohol; it is thus proved that in this latter phosphate than a richer one containing more deleterious case ihe carbon has a condensation double of that which impurities. The value is very much affected by the it possesses in formic ether; and thus the molecule of amount of carbonate of lime, iron, alumina, and fuoride oxalic acid possesses a double capacity of saturation of calcium present; also by its porosity or density, and Analogous considerations are applied to alcohol. They facility with which it can be reduced to a fine powder. were introduced into science for the first time by M. If not in an excessive quantity, carbonate of lime is rather Berthelot, in consequence of his fundamental researches on

an advantage than otherwise in the manufacture of a glycerin. In fact, there where ordinary alcohol produces acid disengaged from it when acid is applied makes a

good-conditioned superphosphate, inasmuch as the carbonic only a single compound, with acids glycerin produces. three. Or in general terms a single molecule of glycerin

mass more bulky and open, and causes it to appear porous may experience three times any one whatsoever of the or honeycombed when finished. reactions which are applicable to ethylic alcohol, either

The presence of a large quantity of iron and alumina separately or simultaneously. Here is, then, a structure in mineral phosphates is objectionable, for they not only which is equivalent to three molecules of ordinary alcohol, absorb acid, but superphosphates made from them have a a fact which is expressed in a single word by saying that tendency to go back," or become insoluble again; thereglyceri is triatomic. These considerations naturally fore the unit percentage of phosphate of lime is worth lead us to the conception of mixed functions so diffused less in minerals containing a good deal of these than in amongst organic compounds. It is thus that glycol: which generally accompanies phosphatic minerals, also

others containing only a little. Fluoride of calcium, which is a diatomic alcohol, gives on oxidation two acids: reduces their value. It wastes acid, and in becoming a first, glycolic acid, which is at once alcohol and a monobasic acid; secondly, oxalic acid, in sulphate of lime its weight is increased to the detriment the molecule of which the acid function is repeated twice of the superphosphate. Silicious matter is a useless inLet us remark, finally, with M. Berthelot, that the atomi: gredient, but a harmless one, except in so far as it causes city of alcohols may be defined in the following manner:

an unnecessary weight to be moved about, and when in An alcohol is monatomic when it contains the elements of excessive quantity reduces the proportion of soluble a single molecule of water replaceable by an equivalent phosphate in the superphosphate to such an extent as to quantity of any acid whatever; it is diatomic when the make it unmarketable. Ordinary mineral superphosphate elements of two molecules of water may be replaced contains þiphosphate of lime equal to 25 to 28 per cent of separately or simultaneously by two molecules either of tribasic phosphate of lime rendered soluble ; and, as it is one and the same acid or of two other different acids, &c. well known that good Cambridge coprolites are capable This atomicity by substitution, thus defined, is secure from all objection, and it ought to be carefully distin. * A Paper read before the Newcastle-upon-Tyne Chemical Society,

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} Mineral Phosphates and Superphosphate of Lime.

49 August 4, 1876. of yielding this of a good chemical composition, and in a allow them to be used safely in the manufacture of superdry powdery condition, the analysis of this mineral may phosphates. be taken as a fair standard upon which to assess the value of others.

Analyses of Suffolk Coprolites.

3. Cambridge Coprolites come from the Upper Greensand in Cambridgeshire, and occur as small" nodular hard Triphosphate of lime..

53'4 бr'3 52'5 56 masses of a grey colour, and are supposed to be fossil ex- Carbonate of lime

175

II6 crement of animals, or occasionally concretions around Iron and alumina

10'4
4.8

8:5 bones, amongst which are found fish-teeth and some ver- Fluoride of calcium 1'4 30 4'3 3 tebræ. Either from the exhaustion of the better sorts or Insoluble matter..

97

I2'2 from imperfect washing the quality has lately somewhat deteriorated, and there is now some difficulty in making

Wicken, Bedfordshire, and Russian coprolites (the first superphosphate from them to contain more than 25 per a poor variety from Cambridgeshire) resemble the Suffolk cent of soluble phosphate.

in their chemical character, and have the following apThe following tests were made before this deterio proximate composition :ration:

Russian.

Bedfordshire. Wicken. of lime..

Triphosphate of lime.. 50

36

33 Carbonate or lime 18:25 12:47 11:66 15'13 13:27

Carbonate of lime Oxide of iron and

Iron and alumina alumina .. 5:30 3:49 4'44 3.82 3:24 Fluoride of calcium

4 Fluoride of calcium. 1.80 2'20 3'00 4'00 4:33

28 Insoluble matter..

43 304 Insoluble silicious

} 6.50 6:04 6:22 8:64 6.93 South Carolina or Charleston Phosphate stands next in matter

importance to Cambridge coprolites as raw material for These coprolites are extracted by washing from a stratum manure-making. This is found in the calcareous strata not more than I foot thick. An average yield is 300 tons of the Charleston basin, occupying an irregular area of per acre, and sometimes enormous prices are paid (up to 50 or 60 miles, and partly underlying the city of Charles£300 per acre) for the privilege of digging them. In ton. It consists of irregular-shaped nodules, associated making contracts for superphosphates it has hitherto been with fossil bones of marine and land animals which are a very common practice for buyers to stipulate for them found embedded in a stratum of clay and sand about to be made from Cambridge coprolites only:

2 feet thick. There are two kinds, the land and the river Coprolites are also raised in Suffolk, Bedfordshire, and deposit. The former is of a fawn-colour, and easily Buckingbamshire, in England; also, largely in France ground, but there is some difficulty in washing away all and in Russia ; but these all contain much iron or silica adhering clay, &c., and it is chiefly kept for home use. and other impurities, which reduce the quantity and de- The river phosphate has become a formidable rival to preciate the value of the phosphate of lime in them. It Cambridge coprolites, and in some respects it is found to is chiefly from the neighbourhood of Boulogne, in the be superior to our native mineral. It is dark, almost black North of France, that the French coprolites are sent over in colour, and rather harder than the land variety, and, to England, and these are largely used for mixing with notwithstanding that it makes a very dark-coloured superricher descriptions of phosphates. They occur as dark phosphate, it is very much liked by manufacturers. It is grey nodules, larger than those from Cambridgeshire, and dredged from the rivers, and the mud and sand are washed are rich in organic remains. An excessive quantity of away on board of the dredgers. silicious matter is their chief impurity, and the cause of The following represents approximately the composition the low percentage of phosphate of lime, which seldom of the river phosphates :exceeds 45 per cent.

Triphosphate of lime

54 Analysis of Boulogne Coprolites.

Carbonate of lime

14 Iron and alumina

3! Triphosphate of lime 46:45

48:0

Fluoride of calcium..
43'3

2.1
Carbonate of lime
II"93
Insoluble silicious matter

15 Iron and alumina

7'29

229 Fluoride of calcium ..

As compared with Cambridge coprolites, this mineral is

2'08 Insoluble silicious matter

more easily dissolved, and a greater portion of the phos23:56 28.1

phates is rendered soluble, but it takes longer to grind, There are also coprolite beds in France, in the Valley and the millstones are more quickly worn. The mineral of the Rhone near Switzerland, and in the Ardennes near | known asto Belgium, where it is thought worth while to go nearly Lot or Bordeaux Phosphate comes from the Departments 200 feet deep through an argiilaceous clay to obtain them; of Lot and Lot et Garonne, in France. It occurs in but the cost of carriage is too great to allow them to be pockets or fissures and veins of the limestone, and also in exported from these places to England.

thin layers, near the surface. These are covered with an Suffolk Coprolites are found adjacent to the London alluvial soil and clay, containing phosphates, but much Clay, and consist chiefly of rolled pebbles, with a small contaminated with iron and other impurities. The proportion of more or less perfect specimens of bones of pockets, of all shapes and sizes, and sometimes reaching various animals, as also some fish and Crustacea. They 100 feet deep, are generally traced and indicated by narrow were formerly regarded as fossilised excrements of ani- vertical veins of deposit, which rise from them to the surmals, for which reason they were called coprolites; but face, and are mostly found on the highest ground.. It they are now supposed to be calcareous pebbles which varies greatly in appearance, texture, and composition. have undergone a peculiar change, and become impreg. Occasionally it is found in snow-white compact masses, nated with phosphoric acid by long continued contact with breaking with an earthy fracture, and of a moderate degree decaying animal and vegetable matter.

of hardness. The more ordinary kinds are of a dark The name pseudo-coprolite has been given from their yellow or brown, dense, and hard; but it is frequently resemblance to the Cambridge coprolites, but they are found of a dark agate colour, somewhat resembling the distinguished from the latter by a brownish ferruginous inside of broken Aints, of a waxy lustre, stratified and incolour and a smoother surface. They are very hard, and tersected with thin layers of oxide of iron. It has the generally contain too much oxide of iron and alumina to appearance of being an aqueous deposit; and the probabl

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CHEMICAL NEWS, 50 Chemical Notices from Foreign Sources.

August 4, 1876. cementing together of lumps of phosphates, bones, &c., crops have been obtained by means of manures rich mainly with more or less alluvial clay and earth, by the percola- in phosphoric acid and in nitrogen. In consequence the tion of dissolved phosphatic matter, may account for the potash of the soil has been taken up in a relatively inappearance, texture, and composition of some portions. creased ratio, and is becoming exhausted. Hence StassThe white specimens are generally the richest, some furt salts are very naturally found to produce a beneficial being as high as 85 per cent, with a minimum (i per cent) effect. of iron, &c., but the bulk of cargoes received here only contain 70 to 72 per cent, and with 4 or 5 per cent of iron, &c. Fossil bones and teeth are found in quantity. A Plan for Rendering Salted Meat more Nutritious, The surface phosphatic earth finds a ready sale on the thereby Preventing Scurvy. By R. GALLOWAY, F.C.S. spot.

Dublin : Hodges, Foster, and Co. Analyses of Two Sample Parcels of Lot Phosphate.

The author's plan is very simple, and, as it seems to us,

very feasible. "He proposes to add to the meat phosphate

Best Quality. Poor Quality of potash, a constituent of which it is deprived by the Triphosphate of lime

67:19 55°45

process of salting. Carbonate of lime

15'31

8:30 Iron, alumina, fluorides, &c.

4'20 12.86 Silicious matter 5820 19:13

CORRESPONDENCE. The best varieties of these phosphates are well adapted for the manufacture of superphosphate. Most of the large Lot mines are owned and worked by English firms, ANALYSES OF MANGANESE ORE. amongst which is a Newcastle Company. To be continued.)

To the Editor of the Chemical News. SIR,—Dr. Phipson's last letter (ChEMICAL News, vol. xxxiv., p. 39) is a remarkable example of argument in a

circle. NOTICES OF BOOKS.

I ask him how he distinguished Mn203 from a mixture

in atomic proportions of MnO and Mno. He replies, Treatment of Ores. By THOMAS Clarke, M.D., and

“ by determining the manganese and oxygen." I point

out that such a method is inadequate, the elementary EDWARD Smith, F.C.S. Torquay: Directory Office.

composition being the same in each case. I ask again, This pamphlet is an account of a patent granted to the how he knows that his assumed Mn203 was not really authors, No. 4448, December 26, 1874. The patentees MnO+MnO2, and I get the reply, " because there is no claim, in addition to improved methods of concentrating MnO in the sample." the ores and of applying a hot or cold blast in roasting Really such an answer is childish, and an insult to the and “chlorodising" the employment of alkaline hyposul. readers of the CHEMICAL News. phites and of ammonia separately or jointly for the solu

As Dr. Phipson is evidently desirous of fencing with tion of the metals, an improved method of separating the question, and apparently has no information to impart, silver, the use of superheated steam if hyposulphites I am unwilling to take up space by further discussing the alone are used, and the passing of galvanic currents to

matter, but will ask Dr. Phipson for full and straightaid the galvanic action, and the mixing with the solution forward replies to the following questions :any requisite quantity of powdered copper precipitate.

1. How did Dr. Phipson ascertain that MnO was not There are also a number of improvements in the con

present, the method which he stated he used for the purstruction of the working plant.

pose having been proved quite inadequate ?

2. If the determination of the total quantity of oxygen Chemical Analyses and Commercial Values and Prices of data for the purpose, as stated by Dr. Phipson, will your

and the total quantity of manganese furnish sufficient Fertilisers Sold in Georgia for the Season 1875-76, to correspondent inform me what proportions of MnO2, which are Appended Formula for Composting Fertilisers Mn2O3, and MnO would be present in a sample containat Home, and Reports of Experiments

. Published under ing 69:62 per cent of manganese and 30:38 per cent of the Direction of the Commissioner of Agriculture for

oxygen ?--I am, &c., the State of Georgia.

ALFRED H. ALLEN, The nature of this pamphlet will be easily understood Sheffield, July 29, 1876. from its title. The fertilisers, or manures as we should call them, met with in commerce in Georgia, have been analysed by Mr. W. J. Land, chemist to the Department CHEMICAL NOTICES FROM FOREIGN of Agriculture, and the results tabulated. called the "commercial values," as contradistinguished

SOURCES. from the “prices,” are, we presume, what are in England known as agricultural values.” It will be remarked Note.-All degrees of temperature are Centigrade, unless otherwise that they approach very closely to the market prices, and expressed. sometimes even exceed them. There appears to be in various parts of America a disposition to condemn chemi- Comptes Rendus Hebdomcdaires des Seances, de l'Acade nie cal manures. The latter of course may be dispensed with

des Sciences. No. 1, July 3, 1876. if all the excrements, liquid or solid, of every being fed Fermentation of Urine.—MM. Pasteur and J. Joubert. upon the produce of the farm can be returned without -An enquiry into the cause of the rapid formation of carwaste to the soil. Where this is not the case a deficiency bonate of ammonia in urine after leaving the bladder. in the ingredients necessary for good crops will gradually arise, and can only be compensated by the use of so-called M. Berthelot.—The author refers to his paper on ferments

Observations on the Foregoing Communication.artificial manures. We are much interested to find that (Comptes Rendus, tome l., p. 983, 1860. in the eyes of American agricultural chemists potash takes a rank higher than it holds-or rather held-in

Third Note on Electric Transmissions through the England. Experiments made with potash salts in this Soil.-M. Th. du Moncel.-Not adapted for abstradion country were often found in past days to give a merely Metallic Nickel Extracted from the Ores of New negative result. The case is now different. Increased | Caledonia.-MM. P. Christofle and H. Bouilhet.—These

3; } Chemical Notices from Foreign Sources.

. August 4, 1876.

51 ores seem to belong to three distinct types--An emerald were a source of heat, and yet the fall of temperature green hydrosilicate, compact and hard, containing 18 to 20 caused by the evaporation of the ether is very distinct. *per cent of nickel and 5 per cent of water; a yellowish As soon as the application of ether ceases the movement green hydrosilicate, more friable, and containing 12 to 15 resumes its normal speed, and remains direct. To repeat per cent of nickel and 10 to 15 of water ; a whitish blue these experiments it is necessary to wait till the interior hydrosilicate, very brittle, and easily crushed with the temperature of the radiometer has become equal to that of fingers, containing merely 6 to 8 per cent of nickel, and as the surrounding air. The author has exposed a radiometer much as 20 per cent of water. The metallic nickel ex- fixed in a dark place to the action of some tubes filled with tracted from these ores contains from 98 to 99-5 per cent phosphorescent powders, rendered very luminous by a of pure nickel.

previous exposure to the sun. There was no movement. Radiometer of Mr. Crookes.-M. G. Govi.—The The author is construđing a radiometer in which the re. author combats the objection raised against his theory fleding surfaces are covered with very phosphorescent from the fact that a radiometer surrounded by a circle of powders, whilst the other surfaces are blackened. lights does not come to a stop. He argues that in a circle New Battery with Peroxide of Manganese.-M. G. of candles, where the intensity of the light varies without Leclanché.—Not adapted for abstraction. ceasing, and where currents of air may cool the small glass case irregularly, the point of thermic equillibrium, which Ditta.-With dry hydrochloric acid gas the result is a

Action of Hydracids upon Selenious Acid.-M. A. would stop the rotation, would only be reached with great compound, Seo HCl. It is a liquid of a pale amber difficulty. He maintains that a uniform temperature ought colour, and is capable of absorbing more hydrochloric to produce continual rotation as well as a continual access acid, forming a solid crystalline body, SeO2, 2HCl. of light. He describes an experiment in which a very sen. Selenious acid absorbs hydrobromic acid very greedily, sitive radiometer, with discs of aluminium polished on one forming a mass of steel-grey crystals, composed of side, and of mica blackened on the other, and placed in a

Se02,2HBr. cylinder of glass, into which the steam of boiling water was passed continuously, began to turn with great velo.

Decomposition of Insoluble Carbonates by Sul. city, the aluminium sides foremost as soon as the steam phuretted Hydrogen.-L. Naudin and F. de Montholon. had begun to raise the temperature of the case. By-and

-Carbonate of baryta suspended in water is completely bye, the temperature remaining invariable, the rotation converted into sulphide of barium by a sufficiently proslackened, and finally stopped as long as the heat was longed current of sulphuretted hydrogen. With other inconstant. When the access of the steam was cut off the soluble carbonates experimented upon the transformation radiometer began to turn in the contrary direction, and is equally complete. continued so for a long time. Any radiometer may be New Method of Substitution of Chlorine and Bro. made to turn in this direction by plunging it into a vessel mine in Organic Compounds.-M.o. Damoiseau.— The of cold water. It begins to move immediately, the author makes use of a peculiar animal charcoal, prepared blackened side of the discs foremost, and only stops after according to the method of Bussy, by calcining a mixture a certain time, i.e., when a new state of thermic equili- of dried blood and carbonate of potash. When cold it is brium has been reached. If the instrument is then taken carefully lixiviated, and calcined again at the highest out of the cold water it begins to turn in the same manner possible temperature. The compounds studied have been as if it had been exposed to light, even though it is all the formed in the pores of this charcoal. time in the most profound darkness. If for the discs of Synthesis of Allantoin.-M. E. Grimaux.—The syn. aluminium and blackened mica we substitute a set of thesis of allantoin and that of parabanic acid realise the burnt mica, blackened on one side, the phenomena are synthetic reproduction of all the derivatives of the paracomplicated, whether because of the bad conductibility of banic group. the mica, or because at a certain temperature the nacreous surface of the mica absorbs much obscure heat, and gives for abstraction.

A New Butylic Glycol.-M. Nevolé.—Not adapted off more gas than the blackened side. Thus, in the case heated to 100°, this radiometer turns regularly for a cer

New Alcoholometric Method by the Distillation of tain time with the nacreous surfaces foremost, then stopped, Alkalinised Spirituous Liquids.-M. E. Maumené.and began to turn in the contrary direction. The author Measure at + 15° C. 200 c.c. of the spirituous liquid in then describes some unsuccessful attempts made to question, brought if needful to 14 or 15 per cent of alcohol eliminate the gases adhering to the discs.

at most; neutralise this volume with caustic soda in

slight excess; distil this liquid to the half or 100 C.C., also Explanation of the Movement of the Radiometer at + 15°, and measure the alcohol by means of a good by the Aid of the Theory of Emission.-M. W. de centesimal alcoholometer. If this liquid, examined with Fonvielle.—The blank surface which reflects the light, and two drops of litmus or with turmeric paper, appears to behaves like an elastic surface, ought to be more energeti- | contain an appreciable quantity of ammonia it is neu. cally repelled than the black if the luminous molecules tralised with a few drops of water, and the 110 to 120 c.c. act like masses - striking the surfaces of the radiometer. made up by the washing-waters are distilled down to But this principle supposes that the speed of the shock is IOO C.c. at + 15o. The alcoholometer on immersion into not superior to the speed of the propagation of molecular this liquid gives its exact percentage of alcohol. movements, which latter is less than that of a ball pro

Detection of Magenta in Wines.-M. E. Jacquemin. ceeding from a revolver. This applies a fortiori to the shock produced by the luminous molecules, whose speed colour separated from the wine by means of agitation with

-The author dyes wool with an ethereal extract of the is a thousand times greater than that of a bullet. In this ammonia and ether. case, therefore, the absorbing or obscure surfaces should be repelled.

On Nitralizarin.-M. A. Rosenstiehl.—The author Radiometer of Mr. Crookes.-M. E. Ducretet.- The H. Perkin.

admits that this compound was first produced by Mr. W. radiometer being exposed to ordinary daylight, its discs take a movement of direct rotation, the black surfaces being repelled. If ether is poured upon the case the

Moniteur Scientifique, du Dr. Quesneville, movement is stopped, and then re-commences in an oppo

July, 1876. site direction. This reaction soon ceases, and we see the Review of Physics.--M, R. Radau.-This consists of discs resume the original direct movement, in spite of the notices of the coefficient of dilation of the air; on electric evaporation on the glass case, kept up by a gentle sprinkling and thermic conductivity; on new pyrometers; on Stoney's with ether. At this moment the rotation becomes more new spectroscope; on the measurement of the refractive rapid than at first, the evaporation seeming to act as if it indices of liquids : and on the relative value of metals

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