X PREFACE 



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 Dictionary. For assistance in the preparation of the 

 index thanks are due to Miss Marion Armour and Mrs. MacFarlane, 

 and for permission to use certain of the figures and illustrations, to the 

 various authors and publishers who granted it. For the excellent man- 

 agement and careful execution of the presswork, the author wishes to 

 thank the publishers, whose courteous and friendly dealings have always 

 made the work easier. 



J. J. R. MACLEOD. 



University of Toronto, 

 Toronto, Canada. 



