Tributes 



well beyond that at which the majority have begun to think of an easier 

 time. So it came about that I found myself overlapping with him in 

 what Cambridge then offered as a course of advanced physiological 

 chemistry. Sheridan Lea had fallen out through illness, and Hopkins 

 was not to arrive till two years later ; meanwhile the class was in the 

 hands of a deputy, whom I found very uninspiring. I recall this, be- 

 cause I remember speaking to Barcroft one day in a mood of dis- 

 couragement with the subject as thus presented, and I remember being 

 surprised at the assurance with which he expressed his conviction that, 

 when we came to the real thing, it would nevertheless be on the chemical 

 side that the main advance of physiology would be found. I think that 

 already, then, while still completing his preparation for the final 

 examination, he must have begun to choose the general direction of 

 what was to be his life's work. Certainly he was ready and eager to 

 begin, when once the examination was out of the way. 



The actual problem on which Barcroft began his researches was 

 suggested to him by Langley, though probably not the method of 

 approaching it. For Langley was not usually interested in chemical 

 methods, but had long been concerned with the salivary glands and 

 with the meaning of the contrasted effects of the chorda and sympathetic 

 nerve-supplies on the secretory activity of the submaxillary gland. 

 Heidenhain had attributed these to the relative predominance in those 

 nerves of secretory and trophic fibres, while Langley believed that 

 everything could be explained by one kind of secretomotor action and 

 the widely different vasomotor effects of the two nerves. Others had 

 suggested that the sympathetic action produced only a squeezing of 

 the acini and ducts by contraction of plain muscle fibres, while others 

 again had interpreted the sympathetic action as simply inhibitory. 

 Langley asked for further light on this controversy, and Barcroft, we 

 may suppose, thought that he could produce some by studying the 

 gaseous metabolism of the gland and its changes with the different 

 kinds of activity. His only predecessors in the attempt had been 

 Chauveau and Kaufmann, eleven years earlier. They wished to test 

 whether the increase of oxidative metabolism which they had observed 

 with muscular activity, as also had Sczelkow and Schmidt twenty 

 years or more earlier still, in Ludwig's laboratory, would be found 

 also with secretory activity of the salivary gland. Chauveau and 

 Kaufmann had used the horse and the natural stimulus of chewing 

 and their results had not been striking or, indeed, uniform. Barcroft 

 decided to use the sub-maxillary gland in the anaesthetized dog and 

 to stimulate the nerves artificially. 



Barcroft had thus chosen his first research objective, but, before he 

 came within striking distance of it, he had to surmount the formidable 



