viii EXTRACT FROM THE PREFACE TO THE FIRST EDITION 



formance ; and it may be said that, except in the case of 

 the simpler experiments and the chemical work as a whole, 

 which each student does for himself, it has been found 

 convenient to divide the class into groups of four, each group 

 remaining together throughout the session. It is possible 

 that some may find a group of four too large a unit, and it 

 is certain that three, or perhaps even two, would be better ; 

 but in a large school so minute a subdivision is hardly 

 possible, without entailing excessive labour on the teachers. 



The systematic portion of the book is so arranged that 

 it can equally well be used independently of the practical 

 work, and aims at being in itself a complete exposition of 

 the subject, adapted to the requirements of the student of 

 medicine. 



As to the matter of the text, it is hardly necessary to say 

 that this book does not aspire to the dubious distinction of 

 originality ; and it is literally impossible to acknowledge 

 all the sources from which information has been derived. 

 In many cases names have been quoted, but names no less 

 worthy of mention have often been of necessity omitted. 



G. N. STEWART. 

 CAMBRIDGE, 



September, 1895. 



