I'REFAI I 



for which he is entirely responsible; and to Doctor E I 

 criticisms, after patienl perusal of the unfinished n 

 inestimable value in its final revision. Acknowledgment 

 to Doctor l\. \V. Scuti and Professor I' K Lloyd, for valual iticism 



and advice, and to tin- former for a chapter on I Appli 



tion of Electrocardiographs." To Ifise Achsa I' M I I thor 



owes a <jreat dclit of trratitude for tic thorough and painstaking way in 

 which she prepared the mannscript for the ] • r her 



tiring endeavors to have the spelling and punctuation in conformity 

 with Webster's Dictionary. For assistance in tl eparation >>f I 

 index thanks arc due to Miss Marian Armour and Mrs M 

 and for permission to use certain of tin figures and illustratioi 

 various authors and publishers who granted it. For th< 

 agemenl and careful execution of the presswork, the author wia 

 thank the publishers, whose courteous and friendly dealings have alwi 



made the work easier. 



J. J. i; m \ 



University of Toronto, 

 Toronto, Canada. 



