PREFACE TO THE SEVENTH EDITION 



IN the present edition the book has been extensively revised. The 

 rapid progress of biochemistry has rendered it necessary to enlarge 

 greatly and practically to rewrite the chapter on Metabolism. 

 Many changes and additions have also been made in the chapters 

 on Circulation, Respiration, Digestion, Absorption, and Internal 

 Secretion. The blood-gases are considered in much greater detail 

 than in the last edition, and more space is devoted to tfce general 

 phenomena of the action of enzymes. The newer work on the 

 relation of the heat production and the chemical changes in muscle 

 to the contraction has been taken account of. The chapters on 

 the Nervous System have been brought up to date. The arrange- 

 ment of the book has been improved, it is hoped, by breaking the 

 longer chapters up into sections, and increasing the number of 

 chapters. Many new illustrations have been added, and many of 

 the old ones redrawn. 



G. N. STEWART. 



CLEVELAND, 



August, 1914. 



