ORGANIC CHEMISTRY 7 



that can be said is that the chemist has realised that which vital 

 chemistry had been realising long before his entry into the field that 

 such and such atomic groupings are stable and capable of free and 

 definite existence, and to this knowledge he has added the fact that 

 vast numbers of other atomic groupings are also capable of free and 

 definite existence. An impartial survey of the facts will, however, 

 serve to show how far we still are from realising vital chemical pro- 

 cesses in the laboratory. The fact that alcohol can be synthesised 

 from carbon and hydrogen through acetylene, &c., has no direct 

 bearing on the formation of alcohol from sugar by the zymase of the 

 yeast-plant. "When we can transform sugar into alcohol in the 

 laboratory at ordinary temperatures by the action of a synthesised 

 nitrogenous organic compound ; when we can convert glucose into 

 citric acid in the same way that Citromyces can effect this transforma- 

 tion ; when we can build up heptane, or cymene, or styrene, or when 

 we can produce the naphthalene or anthracene complex in the labora- 

 tory by the interaction of organic compounds at ordinary temperatures, 

 then may the chemist proclaim with confidence that there is no longer 

 any mystery in vital chemistry. 



It is clear that if chemistry be regarded from what may be called 

 the biocentric point of view, the complete synthesis of an organic 

 compound by pyrogenic methods or by the action of violent reagents 

 is of comparatively little importance. On the other hand, the trans- 

 formation of one vital product into another by laboratory processes 

 even if these are at present not actually analogous to the physiological 

 processes may furnish information of the highest biochemical signifi- 

 cance. The treatment of organic chemistry in this work has accord- 

 ingly been entirely subordinated to the biocentric view of the subject. 

 The book is not to be regarded simply as a catalogue of synthetical 

 products and processes ; neither does it profess to be a practical 

 laboratory guide to the preparation of organic compounds, although, 

 by virtue of its contents, it necessarily comprises both kinds of 

 information. Physiologists will find herein a record of the achieve- 

 ments of synthetical chemistry, chemists will be enabled to ascertain 

 the natural mode of occurrence of organic compounds, and technologists 

 will no doubt find it useful to have the chemical generators of such 

 products as are of industrial value brought conspicuously under notice. 



The importance of emphasising the relationships between the vital 

 products themselves will be realised when it is pointed out that the 

 future development of our knowledge of the chemistry of the living 

 organism must depend largely upon the detection of the chemical 

 antecedents of these products. The discussion of the results of 

 chemical synthesis from this point of view does not come within the 

 scope of the present work, but belongs at any rate in the present 

 state of knowledge rather to the province of physiology. It is for 

 this reason that the necessity for the chemist and physiologist working 



