VI PREFACE. 



of students to work, and before the new buildings were finished 

 the claims of practice began to interfere with my experimental 

 work. I soon found that when a great part of three days is 

 taken up with hospital work, a very few consultations outside 

 will interfere seriously with laboratory work, for just when 

 one has everything prepared for an experiment, one may have 

 to fix a consultation, and all the preparations, which required 

 many hours to make, are rendered useless for the time, and 

 have to be done over again. In consequence of this difficulty I 

 soon determined to follow the plan of working at practice so as to 

 obtain the money which would allow me to pay such a salary to 

 a younger man as would enable him to devote his whole time to 

 laboratory work. I planned the research and experiments, 

 provided the apparatus and material, defrayed all laboratory 

 expenses, and paid my assistant the salary which I was able to 

 earn by my practice, and which at that period of his career he 

 could not earn for himself. We then published the research 

 under our joint names. This arrangement I considered a fair 

 one for us both, as each gave what the other had not got, and 

 we were then able to do the work which neither alone could 

 have done. I have been exceedingly fortunate in getting such 

 able assistants as the late Mr. Pye, Professor Weymouth Eeid, 

 now of Dundee, Professor Cash, of Aberdeen, Dr. Allen 

 Macfadyen, of the Jenner Institute, Mr. T. J. Bokenham, 

 Dr. Kayner Batten, and Professor Tunnicliffe, now of King's 

 College. 



I began to reprint these papers ten years ago, Messrs. 

 Harrison having sent me the first proofs in 1896. The work 

 has been interrupted by other occupations, and also by a 

 serious illness lasting from the summer of 1902 to the 

 autumn of 1903. In consequence of these interruptions 

 and the irregular way in which the work proceeded, various 

 errata have occurred, perhaps the most notable of which is the 

 absence of the fifth lecture, " On the Experimental Investigation 

 of the Action of Medicines," from its proper place, page 322, 

 and its relegation to the Appendix. With this exception, and that 

 of the Harveian Oration, most of the papers are printed in the 

 chronological order of the experiments they record, though not 



