CHEMICAL NEWS, August 4, 1876. Atomicity as a Principle of Classification. certain manner; they have sought to establish between the atoms that compose them precise ties, admitting especially that, not only heterogeneous atoms exhaust among themselves their disposable atomicities, but that these latter may be interchanged between atoms of the same nature. These hypotheses, which are satisfactory enough when we are treating of saturated bodies, become insufficient when we seek to apply them to incomplete bodies. To remove these difficulties it has been proposed to substitute, for absolute atomicity of the elements, admitted 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 being necessarily either even or odd; then the principle of relative atomicities, the atomicity of an element depending on the nature of the body with which it is combined. But these new hypotheses, as M. Berthelot judiciously remarks, render the whole atomic theory illusory and bring it back at last to the law of multiple proportions. However this may be, the atomicity of elements is become in the hands of atomists a fundamental principle of classification, not only for grouping simple bodies in natural families, but even for differentiating mineral and organic bodies. Let us take an example: hydrazobenzol and diphenylendiamin are isomeric. We admit that in the former of these compounds the two atoms of nitrogen, which are not saturated, exchange between themselves their disposable atomicities: C6H5-N-H C6H5-N-H. In diphenylen-diamin the nitrogen is saturated and the two phenylen groups exchange between themselves their two free atomicities: C6H4-N2H2 C6H4-N2H2. In my opinion the atomicity of the elements can only be admitted without question when treating of a definite specific property, as it belongs to atoms, but it is easy to demonstrate that there is nothing of the sort. Phosphorus combines at most with three atoms of hydrogen; it is then here triatomic, but it is pentatomic in contact with chlorine, because there exists a perchloride, PC15; with iodine it forms an iodide, PI2, which corresponds to no known chloride, &c. Nitrogen is monatomic in the protoxide of nitrogen, N2O, as in the hyponitrite of silver of Mr. Divers : 47 It has been sought to explain this anomaly by saying that the atom of mercury occupies two volumes, a supposition inadmissible, for it constitutes a true begging the question. To remove this difficulty there is only, as it seems to me in the present state of science, one plausible explanation, that is, to admit that atomic weight may vary according to the physical state of the bodies; for mercury 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 what becomes then of the invariability of the atomic weights? Second, mercury forms with chlorine two compounds. We admit that it is diatomic in sublimate. Hg2Cl2 = (Hg-Hg)" {CI Messrs. Deville and Troost have found that the density of calomel is 8.2 and as there is no dissociation, according to M. Debray, we have for its molecular weight referre to two volumes, hydrogen being taken as unity On the other hand, 8.2×2 =236 00692 Hg=200=235'5 CI 35'5) The formula of calomel is then HgCl, a compound in whic mercury is monoatomic. Mercury is therefore sometimes monoatomic, sometimes diatomic in contact with chlorine, which amounts to saying purely and simply that it obeys the law of multiple proportion when it forms several compounds with the same element. The difficulties are still greater when we consider the polyatomic metals, such as iron and manganese. Manganese is monoatomic in permanganic acid; diatomic in protoxide of manganese; diatomic or tetratomic in pyrolusite; tetratomic in fluomanganic acid; hexatomic in the manner of ferricum in braunite; probably heptatomic in the perchloride of M. Dumas, &c. According to the preceding considerations it appears to me doubtful whether the atomicity of 48 Mineral Phosphates and Superphosphate of Lime. elements can serve for a principle of classification, whether for simple bodies or for compounds. But the word atomicity has been employed in another and perfectly legitimate sense as representing the relative value of molecules among themselves. Thus understood, this notion becomes an important principle of classification, on which it is proper to insist. In 1838, Graham showed that in neutral phosphate of potassium there are 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 remark that it is impossible to divide by 3 the atoms of oxygen in neutral salts, and that, accordingly, these latter contain probably in their molecules three times more potassium than, e.g., nitrate of potassium. We may make an analogous remark concerning the citrates, which are tribasic; for if the atoms of carbon are divisible by 3, it is not the same with the atoms of oxygen and of hydrogen. In the year 1838, Liebig insisted on the necessity of regarding as polybasic the cyanuric, melonic, comenic, citric, aconitic and aconic, tartaric, malic, and fumaric acids. Other proofs came to the support of this view, which is now adopted by all chemists. It is thus that phosphoric ether contains in the same volume three times as much carbon as nitric ether; and this circumstance is decisive, for it shows that the existence of polybasic molecules is in perfect agreement with the gaseous densities of the ethers. We are thus led with M. Berthelot to consider the molecule of a bibasic acid as resulting from the fusion of two monobasic intimately united. These notions on the acids at first defined in mineral chemistry find their application in organic chemistry, which permits us to deduce from them important rules of classification. Let us cite an example. Formerly we expressed formic acid and oxalic acid by formulæ containing the same quantity of carbon; but whilst the former only gives with bases a single series of neutral salts, the second furnishes likewise acid salts and double salts, which is explained in a most natural manner by admitting that the oxalic molecule contains twice as much of carbon as the formic molecule. On the other hand, experience shows that whilst a litre of formic ether contains the carbon of a litre of alcoholic vapeur, oxalic ether contains in the same volume the carbon of two litres of vapour of alcohol; it is thus proved that in this latter case the carbon has a condensation double of that which it possesses in formic ether; and thus the molecule of oxalic acid possesses a double capacity of saturation. Analogous considerations are applied to alcohol. They were introduced into science for the first time by M. Berthelot, in consequence of his fundamental researches on glycerin. In fact, there where ordinary alcohol produces only a single compound, with acids glycerin produces. three. Or in general terms a single molecule of glycerin may experience three times any one whatsoever of the reactions which are applicable to ethylic alcohol, either separately or simultaneously. Here is, then, a structure which is equivalent to three molecules of ordinary alcohol, a fact which is expressed in a single word by saying that glycerin is triatomic. These considerations naturally lead us to the conception of mixed functions so diffused amongst organic compounds. It is thus that glycol, which is a diatomic alcohol, gives on oxidation two acids: first, glycolic acid, which is at once a monoatomic alcohol and a monobasic acid; secondly, oxalic acid, in the molecule of which the acid function is repeated twice. Let us remark, finally, with M. Berthelot, that the atomicity of alcohols may be defined in the following manner:An alcohol is monatomic when it contains the elements of a single molecule of water replaceable by an equivalent quantity of any acid whatever; it is diatomic when the elements of two molecules of water may be replaced separately or simultaneously by two molecules either of one and the same acid or of two other different acids, &c. This atomicity by substitution, thus defined, is secure from all objection, and it ought to be carefully distin CHEMICAL NEWS, guished from the atomicity of elements or the atomicity of addition which is contestable. Finally, it becomes in the hands of chemists a powerful means of classification, since it allows us to distinguish simple functions: first, repeated functions; second, mixed functions. But the notion of function ought, in the present state of science, to be regarded as the basis of every system of chemical classification. MINERAL PHOSPHATES AND SUPERPHOS. THE rapid development of the manufacture of artificial Deposits of raw phosphatic materials having different composition, as well as in the results obtained from them, characteristics, in physical appearance and in chemical have been found in nearly every part of the globe. The commercial value of these is chiefly regulated by the percentage of tribasic phosphate of lime they contain. The richer they are in this element the more valuable they are (cæteris paribus) for the manufacture of superphosphates. But the amount of phosphate of lime in a mineral cannot be taken as the only criterion of its value, for it sometimes happens that a phosphate containing a lower percentage of this ingredient will make a stronger and better superphosphate than a richer one containing more deleterious impurities. The value is very much affected by the amount of carbonate of lime, iron, alumina, and fluoride facility with which it can be reduced to a fine powder. of calcium present; also by its porosity or density, and If not in an excessive quantity, carbonate of lime is rather an advantage than otherwise in the manufacture of a good-conditioned superphosphate, inasmuch as the carbonic acid disengaged from it when acid is applied makes a mass more bulky and open, and causes it to appear porous or honeycombed when finished. The presence of a large quantity of iron and alumina in mineral phosphates is objectionable, for they not only absorb acid, but superphosphates made from them have a tendency to "go back," or become insoluble again; therefore the unit percentage of phosphate of lime is worth less in minerals containing a good deal of these than in which generally accompanies phosphatic minerals, also others containing only a little. Fluoride of calcium, reduces their value. It wastes acid, and in becoming a sulphate of lime its weight is increased to the detriment of the superphosphate. Silicious matter is a useless ingredient, but a harmless one, except in so far as it causes an unnecessary weight to be moved about, and when in excessive quantity reduces the proportion of soluble phosphate in the superphosphate to such an extent as to make it unmarketable. Ordinary mineral superphosphate contains biphosphate of lime equal to 25 to 28 per cent of tribasic phosphate of lime rendered soluble; and, as it is well known that good Cambridge coprolites are capable * A Paper read before the Newcastle-upon-Tyne Chemical Society. CHEMICAL NEWS, August 4, 1876. Mineral Phosphates and Superphosphate of Lime. of yielding this of a good chemical composition, and in a dry powdery condition, the analysis of this mineral may be taken as a fair standard upon which to assess the value of others. Cambridge Coprolites come from the Upper Greensand in Cambridgeshire, and occur as small nodular hard masses of a grey colour, and are supposed to be fossil excrement of animals, or occasionally concretions around bones, amongst which are found fish-teeth and some vertebræ. Either from the exhaustion of the better sorts or from imperfect washing the quality has lately somewhat deteriorated, and there is now some difficulty in making superphosphate from them to contain more than 25 per cent of soluble phosphate. The following tests were made before this deterioration : These coprolites are extracted by washing from a stratum not more than 1 foot thick. An average yield is 300 tons per acre, and sometimes enormous prices are paid (up to £300 per acre) for the privilege of digging them. In making contracts for superphosphates it has hitherto been a very common practice for buyers to stipulate for them to be made from Cambridge coprolites only. Coprolites are also raised in Suffolk, Bedfordshire, and Buckinghamshire, in England; also, largely in France and in Russia; but these all contain much iron or silica and other impurities, which reduce the quantity and depreciate the value of the phosphate of lime in them. It is chiefly from the neighbourhood of Boulogne, in the North of France, that the French coprolites are sent over to England, and these are largely used for mixing with richer descriptions of phosphates. They occur as dark grey nodules, larger than those from Cambridgeshire, and are rich in organic remains. An excessive quantity of silicious matter is their chief impurity, and the cause of the low percentage of phosphate of lime, which seldom . exceeds 45 per cent. Analysis of Boulogne Coprolites. There are also coprolite beds in France, in the Valley of the Rhone near Switzerland, and in the Ardennes near to Belgium, where it is thought worth while to go nearly 200 feet deep through an argillaceous clay to obtain them; but the cost of carriage is too great to allow them to be exported from these places to England. Suffolk Coprolites are found adjacent to the London Clay, and consist chiefly of rolled pebbles, with a small proportion of more or less perfect specimens of bones of various animals, as also some fish and Crustacea. They were formerly regarded as fossilised excrements of animals, for which reason they were called coprolites; but they are now supposed to be calcareous pebbles which have undergone a peculiar change, and become impregnated with phosphoric acid by long-continued contact with decaying animal and vegetable matter. The name pseudo-coprolite has been given from their resemblance to the Cambridge coprolites, but they are distinguished from the latter by a brownish ferruginous colour and a smoother surface. They are very hard, and generally contain too much oxide of iron and alumina to 49 allow them to be used safely in the manufacture of superphosphates. Analyses of Suffolk Coprolites. Triphosphate of lime.. 50 Iron and alumina 8 20 South Carolina or Charleston Phosphate stands next in importance to Cambridge coprolites as raw material for manure-making. This is found in the calcareous strata of the Charleston basin, occupying an irregular area of 50 or 60 miles, and partly underlying the city of Charleston. It consists of irregular-shaped nodules, associated with fossil bones of marine and land animals which are found embedded in a stratum of clay and sand about 2 feet thick. There are two kinds, the land and the river deposit. The former is of a fawn-colour, and easily ground, but there is some difficulty in washing away all adhering clay, &c., and it is chiefly kept for home use. The river phosphate has become a formidable rival to Cambridge coprolites, and in some respects it is found to be superior to our native mineral. It is dark, almost black in colour, and rather harder than the land variety, and, notwithstanding that it makes a very dark-coloured superphosphate, it is very much liked by manufacturers. It is dredged from the rivers, and the mud and sand are washed away on board of the dredgers. The following represents approximately the composition of the river phosphates: As compared with Cambridge coprolites, this mineral is more easily dissolved, and a greater portion of the phosphates is rendered soluble, but it takes longer to grind, and the millstones are more quickly worn. The mineral known as Lot or Bordeaux Phosphate comes from the Departments of Lot and Lot et Garonne, in France. It occurs in pockets or fissures and veins of the limestone, and also in thin layers, near the surface. These are covered with an alluvial soil and clay, containing phosphates, but much contaminated with iron and other impurities. The pockets, of all shapes and sizes, and sometimes reaching 100 feet deep, are generally traced and indicated by narrow vertical veins of deposit, which rise from them to the surface, and are mostly found on the highest ground. It varies greatly in appearance, texture, and composition. Occasionally it is found in snow-white compact masses, breaking with an earthy fracture, and of a moderate degree of hardness. The more ordinary kinds are of a dark yellow or brown, dense, and hard; but it is frequently found of a dark agate colour, somewhat resembling the inside of broken flints, of a waxy lustre, stratified and intersected with thin layers of oxide of iron. It has the appearance of being an aqueous deposit; and the probabl 50 Chemical Notices from Foreign Sources. cementing together of lumps of phosphates, bones, &c., Analyses of Two Sample Parcels of Lot Phosphate. Triphosphate of lime Carbonate of lime 67.19 15'31 4'20 5'20 55'45 12.86 19'13 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, amongst which is a Newcastle Company. To be continued.) NOTICES OF BOOKS. CHEMICAL NEWS, crops have been obtained by means of manures rich mainly in phosphoric acid and in nitrogen. In consequence the potash of the soil has been taken up in a relatively increased ratio, and is becoming exhausted. Hence Stassfurt salts are very naturally found to produce a beneficial | effect. A Plan for Rendering Salted Meat more Nutritious, thereby Preventing Scurvy. By R. GALLOWAY, F.C.S. Dublin: Hodges, Foster, and Co. THE author's plan is very simple, and, as it seems to us, very feasible. He proposes to add to the meat phosphate of potash, a constituent of which it is deprived by the process of salting. CORRESPONDENCE. ANALYSES OF MANGANESE ORE. 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. I ask him how he distinguished Mn2O3 from a mixture in atomic proportions of MnO and MnO2. He replies, "by determining the manganese and oxygen." I point out that such a method is inadequate, the elementary composition being the same in each case. I ask again, how he knows that his assumed Mn2O3 was not really MnO+MnO2, and I get the reply, "because there is no MnO in the sample." Treatment of Ores. By THOMAS CLARKE, M.D., and Really such an answer is childish, and an insult to the Chemical Analyses and Commercial Values and Prices of Fertilisers Sold in Georgia for the Season 1875-76, to which are Appended Formula for Composting Fertilisers at Home, and Reports of Experiments. Published under the Direction of the Commissioner of Agriculture for the State of Georgia. THE nature of this pamphlet will be easily understood from its title. The fertilisers, or manures as we should call them, met with in commerce in Georgia, have been What are As Dr. Phipson is evidently desirous of fencing with the question, and apparently has no information to impart, I am unwilling to take up space by further discussing the matter, but will ask Dr. Phipson for full and straightforward replies to the following questions: 1. How did Dr. Phipson ascertain that MnO was not present, the method which he stated he used for the purpose having been proved quite inadequate? 2. If the determination of the total quantity of oxygen data for the purpose, as stated by Dr. Phipson, will your and the total quantity of manganese furnish sufficient correspondent inform me what proportions of MnO2, Mn2O3, and MnO would be present in a sample containing 69'62 per cent of manganese and 30:38 per cent of oxygen?-I am, &c., Sheffield, July 29, 1876. SOURCES. ALFRED H. ALLEN. NOTE.-All degrees of temperature are Centigrade, unless otherwise expressed. 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 from the "prices," are, we presume, what are in England known as 66 agricultural values." It will be remarked that they approach very closely to the market prices, and sometimes even exceed them. There appears to be in various parts of America a disposition to condemn chemical manures. The latter of course may be dispensed with if all the excrements, liquid or solid, of every being fed upon the produce of the farm can be returned without waste to the soil. Where this is not the case a deficiency in the ingredients necessary for good crops will gradually arise, and can only be compensated by the use of so-called artificial manures. We are much interested to find that in the eyes of American agricultural chemists potash takes a rank higher than it holds-or rather held-in England. Experiments made with potash salts in this country were often found in past days to give a merely negative result. The case is now different. Increased Comptes Rendus Hebdomadaires des Seances, de l'Acade.nie des Sciences. No. 1, July 3, 1876. Fermentation of Urine.-MM. Pasteur and J. Joubert. -An enquiry into the cause of the rapid formation of carbonate of ammonia in urine after leaving the bladder. Observations on the Foregoing Communication.M. Berthelot.-The author refers to his paper on ferments (Comptes Rendus, tome 1., p. 983, 1860. Third Note on Electric Transmissions through the Soil.-M. Th. du Moncel.-Not adapted for abstraction Metallic Nickel Extracted from the Ores of New Caledonia.-MM. P. Christofle and H. Bouil het.-These CHEMICAL NEWS, Chemical Notices from Foreign Sources. ores seem to belong to three distinct types-An emerald green hydrosilicate, compact and hard, containing 18 to 20 per cent of nickel and 5 per cent of water; a yellowish green hydrosilicate, more friable, and containing 12 to 15 per cent of nickel and 10 to 15 of water; a whitish blue hydrosilicate, very brittle, and easily crushed with the fingers, containing merely 6 to 8 per cent of nickel, and as much as 20 per cent of water. The metallic nickel extracted from these ores contains from 98 to 99'5 per cent of pure nickel. 51 were a source of heat, and yet the fall of temperature caused by the evaporation of the ether is very distinct. As soon as the application of ether ceases the movement resumes its normal speed, and remains direct. To repeat these experiments it is necessary to wait till the interior temperature of the radiometer has become equal to that of the surrounding air. The author has exposed a radiometer fixed in a dark place to the action of some tubes filled with phosphorescent powders, rendered very luminous by a previous exposure to the sun. There was no movement. The author is constructing a radiometer in which the reflecting surfaces are covered with very phosphorescent powders, whilst the other surfaces are blackened. New Battery with Peroxide of Manganese.-M. G. Leclanché.-Not adapted for abstraction. Action of Hydracids upon Selenious Acid.-M. A. Ditte.-With dry hydrochloric acid gas the result is a compound, SeO2HCl. It is a liquid of a pale amber colour, and is capable of absorbing more hydrochloric acid, forming a solid crystalline body, SeO2,2HCl. Selenious acid absorbs hydrobromic acid very greedily, forming a mass of steel-grey crystals, composed of— SeO2,2HBr. Radiometer of Mr. Crookes.-M. G. Govi.-The author combats the objection raised against his theory from the fact that a radiometer surrounded by a circle of lights does not come to a stop. He argues that in a circle of candles, where the intensity of the light varies without ceasing, and where currents of air may cool the small glass case irregularly, the point of thermic equilibrium, which would stop the rotation, would only be reached with great difficulty. He maintains that a uniform temperature ought to produce continual rotation as well as a continual access of light. He describes an experiment in which a very sensitive radiometer, with discs of aluminium polished on one side, and of mica blackened on the other, and placed in a cylinder of glass, into which the steam of boiling water was passed continuously, began to turn with great velo-phuretted Hydrogen.-L. Naudin and F. de Montholon. Decomposition of Insoluble Carbonates by Sulcity, the aluminium sides foremost as soon as the steam had begun to raise the temperature of the case. By-and-converted into sulphide of barium by a sufficiently pro-Carbonate of baryta suspended in water is completely bye, the temperature remaining invariable, the rotation slackened, and finally stopped as long as the heat was constant. When the access of the steam was cut off the radiometer began to turn in the contrary direction, and continued so for a long time. Any radiometer may be made to turn in this direction by plunging it into a vessel of cold water. It begins to move immediately, the blackened side of the discs foremost, and only stops after a certain time, i.e., when a new state of thermic equilibrium has been reached. If the instrument is then taken out of the cold water it begins to turn in the same manner as if it had been exposed to light, even though it is all the time in the most profound darkness. If for the discs of aluminium and blackened mica we substitute a set of burnt mica, blackened on one side, the phenomena are complicated, whether because of the bad conductibility of the mica, or because at a certain temperature the nacreous surface of the mica absorbs much obscure heat, and gives off more gas than the blackened side. Thus, in the case heated to 100°, this radiometer turns regularly for a certain time with the nacreous surfaces foremost, then stopped, and began to turn in the contrary direction. The author then describes some unsuccessful attempts made to eliminate the gases adhering to the discs. Explanation of the Movement of the Radiometer by the Aid of the Theory of Emission.-M. W. de Fonvielle. The blank surface which reflects the light, and behaves like an elastic surface, ought to be more energetically repelled than the black if the luminous molecules act like masses striking the surfaces of the radiometer. But this principle supposes that the speed of the shock is not superior to the speed of the propagation of molecular movements, which latter is less than that of a ball proceeding from a revolver. This applies a fortiori to the shock produced by the luminous molecules, whose speed is a thousand times greater than that of a bullet. In this case, therefore, the absorbing or obscure surfaces should be repelled. Radiometer of Mr. Crookes.-M. E. Ducretet.-The 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 movement is stopped, and then re-commences in an opposite direction. This reaction soon ceases, and we see the discs resume the original direct movement, in spite of the evaporation on the glass case, kept up by a gentle sprinkling with ether. At this moment the rotation becomes more rapid than at first, the evaporation seeming to act as if it longed current of sulphuretted hydrogen. With other insoluble carbonates experimented upon the transformation is equally complete. New Method of Substitution of Chlorine and Bromine in Organic Compounds.-M. O. Damoiseau.—The author makes use of a peculiar animal charcoal, prepared according to the method of Bussy, by calcining a mixture of dried blood and carbonate of potash. When cold it is carefully lixiviated, and calcined again at the highest possible temperature. The compounds studied have been formed in the pores of this charcoal. Synthesis of Allantoin.-M. E. Grimaux.-The synthesis of allantoin and that of parabanic acid realise the synthetic reproduction of all the derivatives of the parabanic group. for abstraction. New Alcoholometric Method by the Distillation of Measure at +15° C. 200 c.c. of the spirituous liquid in Alkalinised Spirituous Liquids.-M. E. Maumené.question, brought if needful to 14 or 15 per cent of alcohol at most; neutralise this volume with caustic soda in slight excess; distil this liquid to the half or 100 c.c., also at +15°, and measure the alcohol by means of a good centesimal alcoholometer. If this liquid, examined with two drops of litmus or with turmeric paper, appears to contain an appreciable quantity of ammonia it is neutralised with a few drops of water, and the 110 to 120 c.c. made up by the washing-waters are distilled down to 100 c.c. at 15°. The alcoholometer on immersion into this liquid gives its exact percentage of alcohol. Detection of Magenta in Wines.-M. E. Jacquemin. The author dyes wool with an ethereal extract of the colour separated from the wine by means of agitation with ammonia and ether. On Nitralizarin.-M. A. Rosenstiehl.-The author admits that this compound was first produced by Mr. W. H. Perkin. Moniteur Scientifique, du Dr. Quesneville, July, 1876. Review of Physics.-M. R. Radau.-This consists of notices of the coefficient of dilation of the air; on electric and thermic conductivity; on new pyrometers; on Stoney's new spectroscope; on the measurement of the refractive indices of liquids: and on the relative value of metals |