PREFACE 



The present work is an attempt to apply facts dis- 

 covered during the study of the physiology of nerves 

 to living processes in general. That mechanism char- 

 acteristic of all living matter which enables it to respond 

 to the external world is best developed in the nervous 

 system. This mechanism may be called the most 

 characteristic thing in life. The chemical accompani- 

 ment, or basis, of this mechanism, discovered by the 

 author in nerve fibers, he has hoped to show exists 

 also in all forms of living matter, both of plants and of 

 animals. It gives a chemical method of distinguishing 

 living from dead tissue, and of measuring the quantity 

 of life. 



This book, therefore, contains somewhat in detail 

 all the essential facts which he with his students has 

 discovered from studies of the chemical changes in 

 nerves accompanying functional change. In the pres- 

 entation of this work, however, many important refer- 

 ences and discussions have been omitted in order that 

 the reader may not lose the main trend of the argument. 

 The facts themselves are nevertheless given in the form 

 of accurate numerical data so that the book may be 

 useful also to the specialist whose interest Ites more 

 directly in the general physiology of the nervous system. 



In an appendix the detailed method for the use of the 

 biometer is added in response to frequent requests of 

 many friends and students who wish to use it for various 

 biological and chemical researches. 



The author is deeply indebted to Professor A. P. 

 Mathews for his criticism, scientific and literary, during 

 the preparation of the work. SHIRO TASHIRQ 



January, 1917 



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