Vlll PREFACE 



Finally, it should be mentioned that the principles of serum diagnosis 

 and therapy are omitted, since these belong to a highly specialized science 

 requiring an intensive training of its own. 



In the hope that the volume may be instrumental in arousing sufficient 

 interest to stimulate a more intensive study of the various subjects 

 which it introduces, a brief bi-bliography is given at the end of each 

 section. The references selected are to papers that are more partic- 

 ularly knoAvn to the author; they are not necessarily the most impor- 

 tant publications on the subject, but are often chosen because of the 

 useful reviews of previous Avork contained in them, rather than because 

 of their own originality. Some of the papers, however, are referred to 

 as authority for statements of fact which may arouse in the reader a 

 desire to ponder for himself the evidence upon which these are based. 

 The references are usually divided into two groups, "monographs" and 

 "original papers," and it is only occasionally that specific reference is 

 made to the former in the context. The original papers, on the other 

 hand, are referred to by numbers. With the general field of the subject 

 so well covered by such excellent textbooks as Bayliss' "Principles of 

 General Physiology," Stewart's, HowelPs, Starling's, and Halliburton 's 

 "Human Physiologies," and Leonard Hill's "Recent and Further Ad- 

 vances in Physiology," the author has felt free to pick and choose from 

 the monographs and original papers, topics that are ordinarily passed 

 over cursorily in the textbook, and when this has been done, the refer- 

 ences are somewhat more extensive. Such is the case for example in 

 the chapters relating to the chemistry of respiration, to the metabolism 

 of carbohydrates and fats, to the problems of dietetics and growth, to the 

 physicochemical basis of neutrality regulation in the animal body, and to 

 the action of enzymes. 



Acknowledgment is gratefully made for the assistance and advice 

 in the preparation of the book, particularly to Doctor R. G. Pearce, for 

 the contribution of several chapters, to which his name is attached, and 

 for which he is entirely responsible ; and to Doctor E. P. Carter, whose 

 criticisms, after patient perusal of the unfinished manuscript, were of 

 inestimable value in its final revision. Acknowledgment is also made 

 to Doctor R. W. Scott and Professor F. E. Lloyd, for valuable criticism 

 and advice, and to the former for a chapter on the "Clinical Applica- 

 tion of Electrocardiographs." To Miss Achsa Parker, M.A., the author 

 owes a great debt of gratitude for the thorough and painstaking way in 

 which she prepared the manuscript for the press, and for her never- 

 tiring endeavors to have the spelling and punctuation in conformity 

 with Webster's Dictionarj'. For assistance in the preparation of the 

 index thanks are due to Miss Marian Armour and Mrs. MacFarlanc, 



