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PREFACE. 



In the following pages I have attempted to present a brief 

 account of the important principles of physiological chemistry 

 in a form suitable for the use of medical students who may be 

 assumed to have completed courses in the elements of general 

 inorganic and organic chemistry. From the very necessities 

 of the case a work of this character, dealing with many topics 

 in an elementary way, must be largely a compilation; in the 

 selection of material, besides consulting the standard hand 

 books, I have made free use of the recent monographs by 

 Cohnheim, Effront and Oppenheimer, as well as of numerous 

 articles in the Zeitschrift fur physiologische Chemie, the 

 Beitrage zur chemischen Physiologic und Pathologic and other 

 journals. As the book is intended for beginners I have not 

 thought it necessary to make any special quotations of litera- 

 ture references. 



In addition to the usual topics of discussion in elementary 

 works on physiological chemistry I have given an outline of 

 the chemical phases of the recent theories of immunity, and 

 a short explanation of the important applications of the 

 methods of cryoscopy and electrical conductivity, and other 

 physical processes, in the field of chemistry related to medi- 

 cine. \York in these latter lines must soon become a part of 

 the laboratory training of medical students. 



A considerable number of illustrative experiments are given 

 in the text, but distinguished by being printed in smaller type. 

 These experiments are sufficiently numerous and comprehen- 

 sive to serve the purpose of a laboratory course parallel with 

 the general course. 



In the work of proofreading I have received very material 

 assistance from my colleague. Dr. W. H. Buhlig, to whom 

 my sincere thanks are due. 



J. H. LONG. 

 CHICAGO, July, 1905. 



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