Sept. 12. 1872J 



NA TURE 



405 



body — water— are the data sufficiently well known. In the 

 c<iurse of the paper the author pointed out a remarkable coinci- 

 ilence lietween cadmium, tin, and lead, in the amount of heat 

 required to raise grara-equivalenls from — 273° to the state of 

 fusion. 



Mr. W. Lant Carpenter made a communication respecting the 

 jire^ence of Alhitnit-n itt Fais^ and on a new method of obtaining 

 ■Stearic and Palmitic Acids. The paper mainly consisted of an 

 account of Dr. Bock's remarkable ])rocess for-the decomposition 

 of Fats which is now being generally adopted on the Continent, 

 in the manufacture of improved stearin candle?. \Vhen fats are 

 decomposed in tiie ordinary process by alkali, a considerable 

 excess of the alkali above the theoretical quantity is required un- 

 less tlie operation is conducted under great pressure, when the 

 ri^k of explosion increases thedisadvaniageousness of the process. 

 When the fats are decomposed by oil of vitriol, or other strong 

 acid (the method usually adopted in England), a considerable 

 proportion of the fat is lost by being charred and burnt, and 

 I hat which remains is so blackened tliat it is necessary to distil 

 it, an operation of expense and of danger owing to the risk of 

 fire or explosion. All these advantages are obviated by the use 

 of Prof. Bock's process. Dr. Bock has shown that most neutral 

 fats are made up of minute globules surrounded by albuminous 

 envelopes, which form from t to I '5 percent, of the weight of the 

 fat, and he considers that the action of the'alkali, acid, or of heat 

 or pressure was to] break up these albuminous envelopes. The 

 destroyed envelopes had a remarkalile power of attracting the 

 colouring matters contained in the fat or produced therein during 

 the action of the acid or alkali. The existence of the albumen 

 may be demonstrated by dissolving the fat in ether or benzol and 

 adding water to the solution, or by boiling the fat with a strong 

 solution of oxalic acid. In each case the albumen envelopes 

 collect at tlie plane of juncture between the two liquids. In the 

 new process the envelopes are broken up by the action of a small 

 quantity of strong sulphuric acid for a limited time only and at a 

 given temperature. Tlie fat is then poured away from the 

 destroyed envelopes and is ready for decomposition by wafer in 

 open tanks. This operation requires some time for lis comple- 

 tion ; its progress may be readily determined by a microscopic 

 examination of the cryst.allised falty acid formed by slowly cool- 

 ing a thin layer upon a glass slide. When the process of decom- 

 position is at an end, the solution of glyce rine is drawn off purified 

 and concentrated for sale. The fatty acids thus obtained amount 

 to 34 percent, of the original fat : they ai'e however far from pure 

 and contain more or less brownish or black matter. By submit- 

 ting the fatty acids in open tanks to the action of a dilute solution 

 of certain oxidising agents, the dark coloured matters are partially 

 oxidised and their specific gravity is so far increased that when 

 the oxidation has proceeded far enough, they readily subside 

 together with the envelopes to the bottom of the tank, and the 

 supernatant fatty acids are rendered comparatively good in 

 colour. After two or three repetitions of this process the resul- 

 tant stearin is hot and cold pressed in the ordinary manner. The 

 acid thus obtained is of a better quality, has a higher melting- 

 point, and is yielded in greater quantity than that obtained in the 

 ordinary way. 



Mr. J. F. Walker contributed a paper On Dinitrobrcnibenzene, 

 and Dr. Wright gave an account of the continuation of his 

 experiments on A'nv Derivatives from Morphine and Codeine. 



Mr. John WilHams described an improved method of preparing 

 Cuaranine, the active principle of Giiaratia, the fruit of the 

 Paulina sorbilis, which is used by the Amazonian Indians for an 

 infusion. This principle was isolated by Stenhouse, and pro- 

 nounced by him to be identical with theine or caffeine, the active 

 substance contained in tea and coffee. In the author's process 

 the guarana is reduced to fine powder mixed with one-third of 

 its weight of hydrate of lime and moistened with water It is 

 then allowed to stand for a couple of hours and thoroughly dried 

 at a gentle heat. The mixture is exhausted with boiling benzol 

 filtered, the benzol distilled off, when a small quantity of hght 

 coloured oily matter remains. This is treated wiih hot water 

 and heated for some time over the water bath, filtered through 

 a moist filter, and after concentration, the solution is set aside to 

 crystallise. In about twenty-four hours the guaranine separates 

 out perfectly pure. The same process is applicable to tea, but 

 the author is inclined to believe that guaranine differs in several 

 particulars — taste, solubility in water, &c. — from theine. 



Mr. Wanklyn described a method of analysing the Coinfouiid 

 Ethers — acetic ether, for example. It consisted in determining 



ihe amount of alcohol liberated in the decomposition of the ether 

 by the known methods of alcoholimeti-y. The complete proxi- 

 mate analysis of a compound ether is thus rendered possible. 



Prof. Crum-Brown made a brief communication on the sub- 

 ject of Chemical Nomenclature. Setting aside the trivial or 

 proper names (names which are simply arbitrary words or marks 

 e.ach indicating in virtue of a convention applicable to each 

 individual case, a particular substance), there are two systems 

 or kinds of systems of chemical nomenclature. These may be 

 distinguished as ist, the composition system, and 2nd, the 

 functional or relational system, or class of systems. In the first 

 the name of a compound indicates the elements or radicals con- 

 tained in it, and sometimes their proportions. Thus Chlorna- 

 trium, Chloriod, Dreifach chloriod, Silicium wasserstoff, &c. In 

 English we have few names so distinctly compositional in form 

 (we have indeed. Zinc methyl and all the other allied names) but 

 many of our names, although apparently functional in form, are 

 really compositional. Thus, chloride of A means with us 

 nothing more than, or different from, a compound containing the 

 elements chlorine and A : and chloride of sodium, chloride of 

 iodine, ter-chloride of iodine, siliciureted hydrogen, not only re- 

 present the same substances as the German names just quoted, 

 but tell us neither more nor less about the substances than these 

 German names do. On the other hand, functional names 

 present the chemical relations between substances. We may 

 take as examples such names as the anhydride, the amide, the 

 aldehyde, the nitride of acetic acid. These derivatives of acetic 

 acid contain no acetic acid, but they stand in certain definite 

 relation to that substance, and he anhydrides, amides, aldehydes 

 and nitrides of other acids stand in the same relation to them. 

 What is still, notwithstanding the efforts of modern chemists, 

 the common popular' nomenclature of salts, although originally 

 intended as a compositional nomenclature, might, with perfect 

 consistency, be retained as a functional nomenclature. The 

 objection to the term " muriate of soda " was that the substance 

 so named contains no soda. But the amide of benzoic acid con- 

 tains no benzoic acid. Soda contains oxygen ; muriate of soda 

 contains none (unless chlorine be an oxide), but the nitride of 

 benzoic acid contains no oxygen, although the acid itself does. 

 The name muriate of soda originally meant the compound o{?.xA\y- 

 drous muriatic acid, 2HCI — H-O, and anhydrous soda Na-0 - 

 (2HCI — H-0)-fNa"0. We may now, il we please, use the 

 name to mean the result of the action 2HCl4-Na-U - H'-O. If 

 we do so, the name becomes a function.al one, and the phrase 

 "muriate of," or, what is neither better nor worse, "hydro- 

 chlorate of," expresses the complex operation. Addition of 

 hydrochloric acid and simultaneous separation of water. Simi- 

 larly, in the case of such names as sulphate of potash, nitrate of 

 oxide of silver, &c., the phrases "sulphate ol," "nitrate of" 

 express the complete operations, addition of sulphuric, or nitric 

 acid, and simultaneous separation of water. 



While the old view that salts are compounds of anhydrous 

 acids and anhydrous bases is now abandoned by most theoretical 

 chemists, a relic of this view still remains in the most advanced 

 systems of nomenclature, producing an inconsistency really in- 

 convenient to the teacher and student. 



The objection taken to the name hydrochlorate of soda was 

 not only that the substance contains no soda, but also that it 

 contains no hydrochloric acid. This objection is perfectly valid 

 against the name as a compositional one, but does it not equally 

 hold against the words sulphate, nitrate, acetate, &c. ? If we 

 are to have liydric sulphate and hydric acetate for sulphuric and 

 acetic acids, why not hydric muriate for muriatic acid ? That 

 this question is not altogether an absurd one will be obvious if 

 we consider that all chlorides are not muii.ites. Those substances 

 which are by general consent called salts stand in a definite 

 genetic relation to the corresponding acids (or, the hydiic salts of 

 the series), and it is inconvenient to have the same general name 

 — chloride — applied to substances which do stand in this relation 

 to hydrochloiic acid, and also to those which do not. We may 

 divide the chlorides into two groups, very different in character 

 in their extreme members, and gradually shading into one 

 another. We may take chloride ot sodium as a representative 

 of the one, and the chloride of phosphorus as a representative 

 of the other. Chloride of sodium is a muriate ; the chloride of 

 phosphorus might be better described. We may call the acids 

 and acid anhydrides negative, the hydratic bases, anhydrous 

 bases positive — arranged in a series, we finct the series a con- 

 tinuous one from the most positive or basic oxides or hydrates 

 to the most negative ; it is however convenient to have a zero 



