TREFACE. IX 



one of the first students in his new Institute, in which he 

 delivered his first lecture shortly after I went. At that time 

 he was busy furnishing his new laboratories and devising new 

 instruments for artificial respiration, for measuring blood 

 pressure and the speed of circulation, for artificial circulation 

 in excised organs and for interchange of gases. He started 

 me on a research, having for its subject the independent 

 contraction of arterioles and capillaries when separated from 

 nerve centres. He liked to be present himself, and indeed to 

 perform most of the experiments on this subject; but in the 

 intervals when he was otherwise engaged I made some ex- 

 periments on the effect of nitrite of amyl and nitrite of soda. 

 These were only intended as by-play, but the research on 

 contractility took so long that Ludwig thought it better to 

 publish a paper on nitrite of amyl with only a general mention 

 of the work on contractility in order to secure priority. I 

 intended to continue it after leaving his laboratory, but when 

 I came to London my time was so much taken up with other 

 things that it became impossible. 



In 1871 I began to write the Experimental Investigation 

 of Medicines, with the intention of expanding it into a complete 

 text-book on "Experimental Pharmacology." Before the part 

 dealing w4th the circulation, however, had been finished, I 

 accepted the late Sir John Burdon Sanderson's invitation 

 to join him in writing a Handbook for the Physiological 

 Laboratory to which I was to contribute the section on 

 Digestion and Secretion. As I performed every experiment 

 mentioned in it and repeated several of them many times, the 

 writing of this short section involved incessant work in the 

 laboratory for more than two years. As an examj)le of this 

 I may mention that the statement at page 84 of the text-book 

 "that pepsine, if absolutely pure, gives no xanthoprotein 

 re-action," cost me many weeks' work. In 1873 and 1874 

 I was engaged with Sir Joseph (then Dr.) Eayrer in examining 

 the action of snake venom and with Dr. Pye Smith on a report 

 to the British Association on Intestinal Secretion. The 

 re-building of the school at St. Bartholomew's Hospital caused 

 an interruption in my laboratory work of nearly four years, 



