84 



NATURE 



[May 28, 1903 



to which the elements, when arranged in the order of 

 their atomic weights, take their place on a kind of 

 chessboard, elements resembling one another being in 

 the same row, have led to the prediction of the existence 

 of new elements ; and even unpredicted new elements, 

 such as the remarkable series discovered by Lord Ray- 

 leigh and by Sir William Ramsay, have had a fairly 

 comfortable place found for them by extending the 

 chessboard on ground to which it had some legitimate 

 claims. 



Inorganic chemistry has developed recently very 

 largely on the physical side. In much of the work, 

 notably in the applications of thermodynamics (and 

 especially of the researches of Willard Gibbs, whose 

 death we lament), the atomic theory plays no part, or 

 but a small one. In the great studies on solutions, 

 however, originated by van 't Hoff, Arrhenius, and 

 Ostwald, the fruitful ion theory formulated by these 

 chemists can hardly be regarded as independent of the 

 atomic theory. And yet, in his last book on inorganic 

 chemistry. Prof. Ostwald employs " the forms of the 

 atomic hypothesis as sparingly as ever the present use 

 of language will permit."^ 



In what has preceded, the atomic theory has been re- 

 garded from the point of view of utility. Of its utility 

 to chemistry there can be no doubt. It helps us to 

 describe complicated phenomena briefly. The atomic 

 formula CH3.COOH reminds organic chemists at a 

 glance of a very large number of properties of acetic 

 acid. But, many will ask, is this atomic theory some- 

 thing more than useful ? Is it really true ? 



The subject has been much discussed of late both by 

 men of science and philosophers.^ One school regards 

 the methods of experimental science as capable of yield- 

 ing generalisations that are absolutely true, and some 

 of the members of this school do not hesitate to say 

 that the atomic theory is absolutely true. Sir Arthur 

 Riicker concluded his brilliant address to the British 

 Association in 1901 by declaring that " we have a right 

 to insist— at all events till an equally intelligible rival 

 hypothesis is produced — that the main structure of our 

 {i.e. the atomic) theory is true; that atoms are not 

 merely helps to puzzled mathematicians, but physical 

 realities." Even in this most positive assertion of Sir 

 Arthur Riicker with regard to the existence of atoms 

 there remains a shade of doubt. Lord Kelvin, in a 

 subsequent speech, showed that in his mind, at any 

 rate, there was none. 



There is, however, another school, the origins of which 

 go back far, but which is identified chiefly with Kirchhoff 

 (the discoverer with Bunsen of spectrum analysis), and 

 with his disciples Mach and Ostwald in Germany, and 

 Karl Pearson in England. According to this school, 

 the discovery of " causes " and of ultimate truths is not 

 the business of experimental science. The object of 

 science, according to Kirchhoff, is to describe natural 

 phenomena in the simplest way possible. If a theory like 

 the atomic theory helps us to describe observed pheno- 

 mena more simply and to discover new ones, let us use it 

 by all means. But (they would say) since the existence 

 of atoms cannot be verified directly,^ it is really useless 

 for scientific purposes to discuss whether the theory is 

 true or not. Obviously, science here abandons those 

 claims to finality which have been insisted on so strongly 

 by the older and more orthodox school, for our simple 

 descriptions are liable at any moment to be replaced by 

 descriptions still more comprehensive and still more 

 simple. It would be hard indeed to prove that any 

 given theory has attained a maximum of simplicity in 

 summarising the facts with which it deals. 



1 " Principles of Inorganic Chemistry." Translated by A. Findlay, 1902, 

 p. 146. (Macmillan and Co., Ltd.) 



- See Prof. James Ward's " Naturali'm and Agnosticism," 2 vols., 1830. 



3 " No physicist or chemist can produce a single atom sei ar.Ued from all 

 its fellows and show that it possesses the elementary properties he assigns 

 to it" (Sir A. Riicker, loc. cit.). 



NO. 1752, VOL. 68] 



Kirchhoff 's self-denying ordinance on the part of 

 science leaves, no doubt, a wider field open to the meta- 

 physicians. But qui trap embrasse mal itreint; and 

 the limitations of scientific claims which he advocates- 

 may well strengthen science in her own proper borders. 



The atomic theory has had a long and venerable his- 

 tory; the "solid, impenetrable" particles of Newton 

 were originated by the Ionian philosophers in the fifth 

 century B.C. A hundred years ago the genius of Dalton 

 gave the theory a fresh and still unfinished career of 

 usefulness, and whether we consider it in the light of a 

 truth that cannot ever disappear from science, or rather 

 as an engine serving to fashion and unite our ideas, 

 possibly to be replaced later by an intellectual 

 mechanism still more efficient, our debt to Dalton re- 

 mains one of the greatest that the world owes to its- 

 great men. P. J. Hartog. 



NOTES. 

 A SPECIAL meeting of the Physical Society will be held 

 on Friday, June 5, at 5 p.m., at University College, when 

 Prof. Rutherford, of Montreal, will read a paper on radio- 

 active processes. A discussion will follow, in which it is 

 hoped several prominent physicists will participate. 



In reply to a question asked in the House of Commons- 

 on Tuesday, Mr. Balfour stated that the Government would 

 contribute to the funds required to send the relief ship 

 Morning to the Antarctic at the end of this year, to ensure 

 the safety of the officers and men of the Discovery, now 

 ice-bound in Antarctic seas. 



The ninth quinquennial conference of the States adhering 

 to the International Telegraph Convention was opened on 

 Tuesday Wy the Postmaster-General, Mr. Austen Chamber- 

 lain, M.P. The business of the conference will go on from 

 day to day until the end of June. Mr. J. C. Lamb, C.B., 

 C.M.G., the principal delegate of Great Britain, was chosen 

 president of the conference, and Mr. John Ardron and Mr. 

 P. Benton vice-presidents. 



M. Henri Becquerel, Paris, and Prof. A. Righi, 

 Bologna, were elected honorary fellows of the Physical 

 Society of London at the last general meeting. 



The Daily Mail announces that Mr. Andrew Carnegie 

 has offered to subscribe 10,000/. towards the erection of an 

 experimental tank for testing ship models, as a memorial 

 to James Watt. 



Mr. Andrew Carnegie has offered to give 200,000/. for 

 a building for the American engineering societies. It is, 

 says Science, to be situated in New York City, and will 

 provide an auditorium, a library and headquarters for five 

 engineering societies. 



The death is announced of Prof. C. A. Bjerknes, pro- 

 fessor of pure mathematics at the University of Christiania, 

 at the age of seventy-eight, and of Dr. G. C. Dibbits, 

 formerly professor of chemistry at Utrecht, at the age of 

 sixty-four. 



The death is announced of M. F^lix Worms de Romilly, 

 a former president of the French Physical Society, who 

 served for many years on the council, and who in addition 

 contributed liberally towards the cost of certain publica- 

 tions undertaken by the Society. 



The Bulletin de la Clause des Sciences (Brussels) 

 announces the death, at the age of seventy-six, of M. 

 Charles de la Valine Poussin, professor of mineralogy and 

 geology of the University of Louvain, and author of im- 

 portant geological papers published in the Bulletin itself 



