ON THE PHYSICAL VIEW OF NATURE. 



159 



The ideas through which unity and coherence have 

 been introduced into the many different trains of reason- 

 ing which were bent upon unravelling the mysteries 

 of chemical affinity came from an unexpected quarter 

 from the country which, in the early part of our 

 century, had become, through Berzelius, the centre of 

 a great school of chemical research. Prof. Ostwald, 

 in his recent historical sketch of the doctrines of 

 chemical affinity, dates the latest period from the year 

 1886, 1 when Svante Arrhenius published his theory as. 



Arrhenius. 



of the chemical solutions decomposed by the galvanic 

 current, the so-called electrolytes. That the reader 

 may understand what importance belongs to this latest 

 development of physical chemistry, I must go further 



tinguish herself in the wider 

 sphere of general or physical 

 chemistry as much as she has 

 done in the past by the extreme 

 and one -sided culture of organic 

 or structural chemistry, it will be 

 largely owing to the influence of 

 the school of Ostwald and that 

 of the industrial factor mentioned 

 in the text, which nowadays em- 

 phasises as much the economical 

 control of chemical reactions as 

 it did formerly the discovery and 

 preparation of new compounds. 

 The ultimate success in the in- 

 dustrial preparation of artificial 

 indigo, which was theoretically 

 long known, is an example well 

 worth careful attention. 



1 Prof. Ostwald had himself 

 about the same time made an 

 attempt in the second volume of 

 the first edition of his great work 

 to unite the disjecta membra of 

 physical chemistry, notably of the 

 theory of affinity, into a system- 

 atic whole. This first attempt 

 may have contributed quite as 



much as the special labours of 

 others, among whom he mentions 

 specially Helmholtz, Van't Hoff, 

 Duhem, Planck, and Arrhenius, to 

 create an era in chemistry. It 

 may also be noted that, like every 

 other important step in chem- 

 istry, this latest theoretical phase 

 is characterised by violent contro- 

 versies. These became more pro- 

 nounced as Prof. Ostwald intro- 

 duced into the second edition of 

 his work the idea of " energetics " 

 as a general and sufficient basis 

 for the whole of physics and 

 chemistry ; making a very emphatic 

 protest against the older physical 

 theories, based upon attractions, 

 atomism, or kinetics, which he 

 stigmatises as mechanical. On 

 this important controversy I shall 

 have to report at the end of the 

 present chapter, where I shall also 

 give the full literature of the sub- 

 ject. In the meantime, see also 

 Ostwald, ' Allgemeine Chemie,' vol. 

 ii. part 1, preface, and part 2, p. 

 182 sqq. 



