PREFACE. 



IT has been my desire in the preparation of this work to 

 consider the subject of Physiological Chemistry from the 

 point of view of the biologist and the physician rather than 

 from that of the chemist, and, accordingly, I have adopted a 

 classification of the subject based entirely on morphological 

 or physiological considerations. Whilst I have, however, 

 given special prominence to all those facts which offer at 

 present the greatest interest to the biologist, and have kept 

 in the back ground such as only possess interest to the pure 

 chemist, because involving some doubtful question of consti- 

 tution, I have, nevertheless, taken care that no chemical 

 fact and even that no chemical speculation should be 

 omitted which appeared likely to throw light upon a bio- 

 logical question. 



In the present volume the chemical composition of, and 

 the chemical processes relating to, the elementary tissues of 

 the body are treated of, the blood, lymph, and chyle being- 

 included in that classification. This volume forms a com- 

 plete and independent work, though it is intended that it 

 shall, within twelve months, be followed by a second volume, 

 in which the chemistry of the chief animal functions will be 

 treated of. 



Some may be inclined to remark that I have introduced 

 into this work too large a reference to the sciences of 



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