104 



CHEMISTKY. 



tributed. The laws of chemistry, like those of 

 astronomy, are now so well understood and 

 generally accepted, that we are not surprised 

 that the year has not witnessed the promulgation 

 of any striking original theory, which would re- 

 quire a modification of prevalent views upon 

 the subject. No addition has been made to 

 the number of simple elements ; but, with re- 

 gard to those quite recently discovered and 

 obtained in considerable quantities (see INDIUM, 

 MAGNESIUM and THALLIUM), some new and inter- 

 esting facts have been brought to light. The 

 editor would again acknowledge his indebted- 

 ness to the American Journal of Science and 

 Arts (specially to the valuable memoranda fur- 

 nished to that publication by Professor Wol- 

 cott Gibbs), to the London Chemical News, 

 (now reprinted in this country), the Philosophi- 

 cal Magazine, and the English and Continental 

 scientific reviews. (See also, ELECTRICITY and 

 METALS). 



The New Chemical Calculus, The subject 

 of a new chemical calculus was widely discussed 

 during the year in the scientific circles and 

 journals, many of the most distinguished chem- 

 ists of Europe taking part in the controversy. 

 The views of Professor Kekule, published in 

 the Chemical News, are quoted by the American 

 Journal of Science, as clearly stated and at the 

 same time just. They are in substance as fol- 

 lows: 



The author begins by saying that the ques- 

 tion, whether atoms exist or not, has but little 

 significance in a chemical point of view ; its 

 discussion belongs rather to metaphysics. In 

 chemistry it is only necessary to decide whether 

 the assumption of atoms is an hypothesis 

 adapted to the explanation of chemical phe- 

 nomena. He has no hesitation in saying 

 that, from a philosophical point of view, he 

 does not believe in the actual existence of 

 atoms, taking the word in its literal significa- 

 tion of indivisible particles of matter. But, as 

 a chemist, he regards the assumption of atoms 

 not only as advisable, but as absolutely neces- 

 sary in chemistry. Should the progress of 

 science lead to a theory of the constitution of 

 chemical atoms, important as such a knowledge 

 might be for the general philosophy of matter, 

 it would make but little alteration in chemis- 

 try itself. The chemical ato.m will always re- 

 main the chemical unit. "We may, in fact, 

 adopt the view of Dumas and of Faraday, 

 "that whether matter be atomic or not, this 

 much is certain, that granting it to be atomic, 

 it would appear as it now does." Professor 

 Kekule then proceeds to an examination of the 

 paper read by Sir Benjamin Brodie, before the 

 Royal Society, entitled "The calculus of 

 chemical operations, being a method for the 

 investigation, by means of symbols, of the laws 

 of the distribution of weight in chemical 

 change; Parti. On the construction of chemi- 

 cal symbols." It was the publication of this 

 paper, which gave an impulse to the general 

 discussion of the subject. "With regard to the 



published results and especially the formulae 

 given for the elements and compounds, the 

 critic observes that they possess no advantage 

 over the views now universally received. They 

 contain, like those hitherto in use, only statics 

 and no dynamics; and although we are assured 

 "that they express by symbols the exact facts 

 of chemistry," it is impossible not to perceive 

 that these . symbols involve an almost un- 

 limited number of hypotheses for which there 

 is no proof whatever. For the elements, 

 Brodie comes to the conclusion that there ex- 

 ist three groups, expressible by. the symbols 



x y* x+y* 



All elements belonging to the third group 

 (chlorine, bromine, iodine, nitrogen, etc.) are 

 regarded as compounds. They are not indeed 

 supposed to contain two kinds of matter at 

 present unknown in the separate state, but the 

 much less admissible hypothesis is made that 

 they consist of a constituent hitherto unknown 

 in the isolated state, combined with hydrogen. 

 Such an assumption, the critic regards as so 

 directly at variance, not only with all views 

 hitherto received, but with the entire range of 

 known facts, that it requires to be tested with 

 all possible circumspection. Had the author 

 of the " Calculus of Chemical Operations" 

 merely expressed an opinion that the formula) 

 which he has constructed for elements and 

 compounds are " one of the different expres- 

 sions" which, according to the principle of 

 prime factors, are deducible from the known 

 facts connected with relations of volume, every- 

 body would have agreed with him. But Sir 

 Benjamin Brodie goes further. Among other 

 things he suggests the theory that many of the 

 substances now regarded as elements contain 

 hydrogen, and that even if the elements which 

 are combined with hydrogen in those com- 

 pounds do not exist in a free state, in our earth, 

 they may possibly exist in that state in other 

 parts of the universe. No one, continues 

 Professor Kukele, will maintain that the 

 bodies which we now call elements are neces- 

 sarily and absolutely undecomposable. Buf 

 if, on the other hand, it be asserted that our 

 existing elements are actually of compound na- 

 ture, the establishment of such a proposition 

 will certainly require more than the simple ob- 

 servation that a result of this kind may possi- 

 bly be deduced from reasoning founded upon 

 hypothesis. We shall at least require proof 

 that such an assumption is calculated to lead 

 to useful results, and that it presents decided 

 advantages over our present views. If it be 

 maintained that many of the substances now 

 regarded as elementary contain a substance at 

 present unknown in the free state, combined 

 with another body hydrogen, for example 

 which we do not know in that state, we may 

 certainly require the assertion to be proved by 

 the actual separation of hydrogen from those 

 substances. Until that is done, it is safe to 

 stand by the principle announced by Dalton, 

 " that a substance, till it is decomposed, must 



