GENERAL PREFACE. 



THE subject of Physiological Chemistry, or Biochemistry, is 

 enlarging its borders to such an extent at the present time, 

 that no single text-book upon the subject, without being 

 cumbrous, can adequately deal with it as a whole, so as to 

 give both a general and a detailed account of its present 

 position. It is, moreover, difficult, in the case of the larger 

 text-books, to keep abreast of so rapidly growing a science 

 by means of new editions, and such volumes are therefore 

 issued when much of their contents has become obsolete. 



For this reason, an attempt is being made to place this 

 branch of science in a more accessible position by issuing 

 a series of monographs upon the various chapters of the 

 subject, each independent of and yet dependent upon the 

 others, so that from time to time, as new material and 

 the demand therefor necessitate, a new edition of each mono- 

 graph can be issued without re-issuing the whole series. In 

 this way, both the expenses of publication and the expense 

 to the purchaser will be diminished, and by a moderate 

 outlay it will be possible to obtain a full account of any 

 particular subject as nearly current as possible. 



The editors of these monographs have kept two objects 

 in view : firstly, that each author should be himself working 

 at the subject with which he deals ; and, secondly, that a 

 Bibliography, as complete as possible, should be included, 

 in order to avoid cross references, which are apt to be 

 wrongly cited, and in order that each monograph may yield 

 full and independent information of the work which has been 

 done upon the subject. 



It has been decided as a general scheme that the volumes 



