H i a 



PKEFACE 



TO 



THE SIXTH EDITION 



I HAVE again subjected the book to a thorough revision, and the 

 changes which are now introduced into the practical exercises are 

 those which experience has shown to be advisable. In the large 

 text it has been necessary to rewrite a good many parts, mainly on 

 account of our increased knowledge of the proteins and of the way 

 they are utilised in the body. The sections relating to blood coagula- 

 tion and to respiration have been much amplified in order to include 

 many facts which are the result of recent research. 



In my endeavour to bring the work abreast of advances in 

 science, and at the same time to keep it within moderate limits, 

 I have to acknowledge help and valuable suggestions from Mr. J. 

 Barcroft, M.A. (especially in connection with Respiration), from 

 Professor T. G. Brodie, F.R.S., and from my two colleagues at King's 

 College, Dr. Lyle and Dr. 0. Eosenheim ; both of these have been 

 of great assistance to me in reading the proof-sheets, and Dr. Lyle 

 is again responsible for the Index. 



W. D. HALLIBUBTON. 



KING'S COLLEGE, 1907. 



JflOS'd 



