440 



NATURE 



[June 2, 1921 



Dalton and Atomic Symbols. 



IN an article in the Moniteur Scientifique Quesne- 

 ville Prof. Maurice Delacre, stimulated by a pas- 

 sage in "The Life and Work of Gerhardt " by E. 

 Gnmaux, severely criticises the attitude which was 

 taken up by Berzelius in his celebrated " Essai sur 

 la th^orie des proportions chimiques " (Paris, 1819) 

 towards the work of Dalton. The chief ground of 

 the criticism is that in this work, the original of 

 which appeared in Swedish in 1818, Berzelius 

 describes his well-known system of chemical symbols 

 without making any mention of the fact that Dalton 

 had more than ten years previously introduced true 

 atomic symbols and used them for the construction 

 of formulae. The passage in the " Essai " of Berzelius 

 reads as though he himself had been the first to con- 

 ceive this happy idea, and has thus given rise to the 

 erroneous view entertained by some writers on the 

 history of chemistry that Berzelius invented atomic 

 symbols, whereas the credit is entirely due to Dalton. 

 Berzelius further, in the opinion of the author, 

 exaggerated the importance of the work of Wenzel 

 and Richter and minimised that of Dalton in con- 



nection with the discovery of the laws of chemical 

 combination, whereas, in fact, these laws were clearly 

 enunciated only after Dalton 's ideas about atoms 

 had become known. Prof. Delacre propounds the 

 thesis that there is only one chemical law of weight,, 

 and this he proposes to call the " law of the symbol," 

 regarding the laws of definite and multiple propor- 

 tions as corollaries of this fundamental law. 



There is here some confusion between experience 

 and theory, and we do not regard this suggestion as 

 judicious. It is, of course, true that Dalton's atomic 

 theory has as necessary corollaries the laws of 

 chemical combination, but the theory rests ultimately 

 on the observations by which these laws were estab- 

 lished, and to these observations it is undeniable that 

 Wenzel and Richter made important contributions. 

 In the matter of atomic symbols Dalton has, in this 

 country at least and in most of the historical works 

 with which we are acquainted, received full credit, 

 and it is with surprise that we learn that some writers 

 still erroneously attribute this important advance ta 

 Berzelius. 



The Melbourne Meeting of the Australasian Association.^ 



II. 



Abstracts of Presidential Addresses to Sections. 



SECTION A (Astronomy, Mathematics, and 

 Physics). — Prof. H. J. Priestley, of the Univer- 

 sity of Queensland, in his presidential address traced 

 the development of the theory of relativity. In dis- 

 cussing the Einstein spectral-line effect, he pointed 

 out that the usual treatment of the question 

 involves the assumption that the time-period of 

 the source is transmitted by the radiation to the 

 observer. He gave reasons for making the alterna- 

 tive assumption that the Einstein interval ds is trans- 

 mitted by the radiation, in which case the displace- 

 ment of spectral lines should arise from a change in 

 the field of the observer, not in that of the source. 

 To meet the possible objection that the usual method 

 of establishing the deviation of light in a gravitational 

 field appears to imply an underlying constant time- 

 period in the radiation, Prof. Priestley showed that 

 the light path in a gravitational field could be found 

 by a method which made no appeal to pre-relativity 

 physics, and implied, therefore, no assumption as to 

 the constancy of the time-period. 



Section B (Chemistry).— Prof. N. T. M. Willsmore, 

 in the course of his presidential address, referred to 

 the indispensable work of British chemists during the 

 war, stating that in the manufacture of explosives 

 and in devising counter-measures against the 

 enemy the chemist held the key to the position. 

 Chemists were needed to deal with poison gas, to 

 supervise water-supply, for the manufacture and use 

 of artificial fog in the Navy, in the munition fac- 

 tories, and in numerous other spheres. In future 

 wars chemistry would play an even greater part, and 

 in the United States the Chemical Warfare Service had 

 been organised as an independent branch of the Army. 

 Prof. Willsmore then indicated the immense amount of 

 work done by the chemists in the explosives and other 

 factories in Great Britain. 



Section C (Geology and Mineralogy). — " Recent 

 Advances in our Knowledge of New Zealand Geo- 

 logy " was the title of the presidential address 

 delivered by Prof. W. Noel Benson. The geo- 



1 Continued from p. aio. 



NO. 2692, VOL. 107] 



logical history . of New Zealand was divided 

 into three major periods, the oldest closing about 

 Carboniferous times, the second in Lower Cretaceous 

 times, and the third at the end of the Pliocene period. 

 Comparative tables showing the classification of the 

 strata in each period by many students of New Zea- 

 land geology illustrate the gradual evolution of the 

 knowledge of New Zealand stratigraphy. It has been 

 customary to consider the complex of gneisses and 

 associated rocks in " Fiordland " as of Cambrian or 

 pre-Cambrian age, but recent work by various inves- 

 tigators tends to show that this view is incorrect. 

 Prof. Benson concludes that while some of the crystal- 

 line complex may be pre-Ordovician, the bulk of it is 

 probably post-Ordovician, and some may be even of 

 Mesozoic age. These rocks have been invaded by 

 more or less gneissic plutonic rocks during a period of 

 orogeny, followed either immediately or at a later 

 orogenic period by massive .plutonic intrusions. To 

 the second period belong the " Maitai " (? Permian) 

 and the " Hokonui " (Trias-Jurassic) systems. The 

 relationship between the Hokonui series and the 

 underlying Maitai series was discussed at length, and 

 the conclusion reached that there is little evidence of 

 a great unconformity, though crust-warping probably 

 occurred. An interesting problem of New Zealand 

 geology, the origin of the Otago schists, was also 

 discussed. These rocks have been assigned to ages 

 ranging from pre-Cambrian to Mesozoic. Prof. 

 Benson suggested that they occurred as a series of 

 sheet-folds, occasionally upturned and crushed, and 

 composed for the most part of the metamorphic equi- 

 valents of Middle and Lower Triassic and Permian 

 formations. The varying views as to periods of 

 orogeny and plutonic intrusion and the general direc- 

 tion of folding were described and a new interpretation 

 of the facts was suggested. Following the Hokonui 

 orogenic movements, marine deposits were laid down, 

 commencing with Middle Cretaceous and extending 

 into Upper Pliocene beds. The diverse views of the 

 relationship between these series were discussed and 

 a complete bibliography of the literature was given. 

 It was pointed out that during the deposition of these 

 marine beds only in Otago is there evidence of a 

 persistent land surface. The affinities of the fossil 



