ox THK I'llYSKJAL VIEW OF NATrKK. 



15 'J 



Tlie ideas through which unity and L-(jhereiiee have 

 been introduced into the many diil'ereut trains of reason- 

 ing whieli were henL upon unnivclhng the myHteries 

 of chemical attinity came from an unexpected quarter 

 — from the country whicli, in the early part of our 

 century, had become, through Jierzelius, the centre of 

 a great school of chemical research. Vroi. Ustwald, 

 in his recent historical sketch of the doctrines of 

 chemical attinity, dates the latest ])eri(jd frum the year 

 188G,' when Svante Arrhenius j)ul)lislied his t]ie<»ry as 

 of the chemical solutions decomposeel liy 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 



Arrbeiiiuit. 



tinguish hert^elf in the wider 

 spliere of general or physical 

 chemistry as much as she has 

 done in the past l>y 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 tiie industrial factor mentioned 

 in the text, which nowadays em- 

 phasises as nmch the economical 

 control of chemical reactions as 

 it (lid formerly the discovery and 

 preparati(jn of new com|)ouuds. 

 The ultimate success in the in- 

 dustrial preparation of artificial 

 indigo, which was theoretically 

 l')ng known, is an example well 

 worth careful attention. 



' 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 rlisjccta mimbnt of 

 l>hysical chemistry, notably of the 

 tlieory of affinity, into a .system- 

 atic whole. This first attempt 

 may have contributed quite a.s 



nmch as the special labours of 

 others, among whom he mentions 

 specially Helmholtz, Van't HoB', 

 Duhem, Planck, and Arrhenius, ti> 

 create an era in chemistry. 1 1 

 may also be noted that, like every 

 other important step in chem- 

 istry, this latest theoretical piia.se 

 is characterised by violent contro- 

 versies. The.se became more pro- 

 niiunced as Prof. Ostwald intro- 

 duced into the second eilition of 

 his work the idea of "energetics" 

 as a general and sufficient basis 

 for the whole of physics and 

 chemistry ; making a very emphatic 

 j)rotest against the older jihysical 

 theories, based upon attractions, 

 atomism, or kinetics, whidi he 

 stigmatises as mechanical. On 

 this important controver.sy I shall 

 have to report at the end of the 

 ])i'csent chajiter, where I shall al.io 

 give the full literature of the sub- 

 ject. In the meantime, see also 

 Ostwald, ' Allgenieine Cheniie,' vol. 

 ii. part 1, preface, and i>art -, p. 

 182 .•«/<]. 



