784 



SCIENCE. 



[N. S. Vol. XVII. No. 437. 



Tliis tone is illustrated by a single quotation 

 from the book before us : " The highest aim 

 of scientific investigation is the discovery of 

 wide-reaching relations between large numbers 

 of facts. Such relations when sufficiently 

 comprehensive are known as generalizations. 

 Beyond these we can not go" (italics ours). 

 A very considerable proportion of the studies 

 of these physical chemists center around the 

 theory of electrolytic dissociation, and this 

 theory is invoked to explain practically all 

 the phenomena of chemistry. Speaking of 

 the fact that perfectly dry sodium does not 

 react with perfectly dry sulfuric acid. Dr. 

 Jones tells us that ' in terms of the theory of 

 electrolytic dissociation and catalysis these 

 facts are just what would be expected, and 

 could have been predicted before they were 

 discovered.' Ostwald shows that in the light 

 of this theory all the reactions and procedures 

 of analytical chemistry become simple and 

 clear. On the other hand, we must remember 

 that the theory itself applies with strictness, 

 as far as it concerns solutions, to those solu- 

 tions only which are at great dilutions, indeed 

 in many cases to those of such dilutions as 

 to be practically unattainable. The theory 

 may be invoked to explain the phenomena of 

 concentrated solutions, multitudinous reac- 

 tions of organic chemistry, reactions which 

 take place at high temperatures, and many 

 others, but in these fields the applicability of 

 the theory is largely a matter of conjecture. 

 In other words, the theory of electrolytic dis- 

 sociation is not the great, universal general- 

 ization we might imagine from the writings 

 of some of its adherents. It represents a 

 truth, but by no means the whole truth. In 

 certain fields, as notably that of analytical 

 chemistry, it is exceedingly useful, though 

 even here it by no means explains everything. 

 It does clear up many points which were for- 

 merly obscure. One can not help sometimes 

 wondering if it is not leading chemistry fully 

 as much back to the views of Berzelius, as 

 carrying it forward into new fields, and 

 whether it may not, like the dualism of the 

 great Swede, some near day meet its Dumas. 

 But even should this be the case, the work of 

 the school of modern physical chemists is of 



inestimable value, and will always stand as 

 one of the greatest advances in the develop- 

 ment of chemistry. The dualistic theory of 

 Berzelius was, after all, never really over- 

 thrown, but lives to-day in the theory of 

 electrolytic dissociation. The mistake of 

 Berzelius was in believing it applicable to all 

 chemical phenomena. The physical chemist 

 of to-day has found a key which fits many 

 locks hitherto inviolable, but it has not yet 

 proved itself to be the master-key. 



In the preface to his book Dr. Jones says : 

 " The aim of this book is to add to the older 

 generalizations those recently discovered, and 

 to apply them to the phenomena of inorganic 

 chemistry in such a way that they may form 

 an integral part of the subject, and at the 

 same time be intelligible to the student. Why 

 should we continue to teach the chemistry of 

 atoms to students on the ground of its being 

 a little simpler, perhaps, than the chemistry 

 of ions, or on any other ground, if we know 

 that it is not in accordance with the recently 

 discovered facts ? Or why should we continue 

 to teach purely descriptive chemistry when the 

 science of chemistry has outgrown this stage, 

 and many of the most important relatipns have 

 been accurately formulated in terms of the 

 simpler mathematics? * * * If a student can 

 grasp the conception of an atom and can not 

 add to this the idea of the atom carrying an 

 electrical charge, his hope of ever learning 

 anything of chemical phenomena in general 

 is not bright. * * * Why should chemists be 

 hampered by being compelled to describe phe- 

 nomena at length when these could be formu- 

 lated in a single line? The time has come 

 when they need not be, and the earlier ele- 

 mentary mathematics is introduced into text- 

 books on chemistry, the better for chemistry 

 and for the chemist." 



While thoroughly carrying out the spirit 

 of the preface, the book is not, perhaps, as 

 radical as might be expected. After opening 

 with an introduction on elements and com- 

 pounds and a chapter on the great generaliza- 

 tions of chemistry — the laws of conservation 

 of mass, of constant proportion, of multiple 

 proportions, of combining weights, the atomic 

 theory and the correlation and conservation of 



