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EXTRACT FROM THE PREFACE TO 

 THE FIRST EDITION 



IN this book an attempt has been made to interweave 

 formal exposition with practical work, according to a pro- 

 gramme which I have followed for some time past in teaching 

 Physiology to medical students on the other side of the 

 Atlantic, and which has, it is believed, proved to be well 

 adapted to their needs and opportunities. It ought, how- 

 ever, to be explained that, for various reasons, a somewhat 

 wider range of experiment is open to the student in America 

 than in this country. But as nobody will use this book 

 except in a regular laboratory and under responsible 

 guidance, it has not been thought necessary to mark in any 

 special manner the parts of the exercises which the English 

 student must do by proxy (that is, learn from demonstra- 

 tions), and the parts he ought to perform for himself. 



An arrangement of the exercises with reference to the 

 systematic course has this advantage that by a little care 

 it is possible to secure that practical work on a given subject 

 shall actually be going on at the time it is being expounded 

 in the lectures. Cross-reference from lecture-room to 

 laboratory, and from laboratory to lecture-room, from the 

 detailed discussion of the relations of a phenomenon to the 

 living fact itself, is thus rendered easy, natural, and fruitful. 



As some teachers may wish to know how a course such as 

 that described in the Practical Exercises may be conducted 

 for a fairly large class, a few words on the method We have 

 followed may not be out of place. It is obvious that many 

 of the exercises require more than one person for their per- 



