60 The Science of Life. 



Du Bois-Reymond was keenly interested in history and 

 philosophy, literature and art. Like Huxley, from 

 whom he differed in most ways very markedly, he ex- 

 celled as a lecturer, impressive even to those who dis- 

 agreed, for his French elegance of style, his Celtic 

 dramatic power, and his strongly developed historical 

 sense were for the time irresistible. An evolutionist 

 and a materialist of a refined sort, he did good service 

 in ridding physiology of the cruder forms of Vitalism, 

 though how far he touched the position of the subtler 

 " Neo-vitalists " is a matter of opinion. In any case he 

 showed the fallacy of the strongly engrained impression 

 that science presumes to give more than proximate 

 explanations of facts. 



Although physiology may become experimental at 

 almost every turn, the phrase "experimental physiology" 

 Experimental m ^y be used in a more restricted sense in 

 Physiology, reference to experiments on living creatures. 

 Whether we put caterpillars into a gilded box and 

 watch for a change in the colour of the pupae, or feed 

 tadpoles with different kinds of food to show that 

 nutritive changes affect sex, or extirpate the thyroid 

 gland of a rabbit to see the effect on the constitution, 

 or stimulate the nerve-centres on the brain of a chloro- 

 formed monkey, we are making experiments on living 

 creatures. [It is here that the problem of the ethical 

 limits of scientific inquiry is raised in many minds, but 

 it should not be restricted to this issue.] 



Though the experimental method was long ago re- 

 sorted to by Harvey, it practically dates from the work 

 of Magendie (1783-1855) and Claude Bernard (1813- 

 1878). In illustration of its use we may refer to the 

 work on internal secretions and on the nervous mech- 

 anism, both very characteristic of modern physiology. 



This unattractive title expresses one of the most sig- 

 nificant of recent advances in modern physiology. The 

 The study stuc ty nas to ^ w i tn the action of various 

 of internal glands on the blood that passes through 

 >ns ' them, and its beginning dates from Claude 

 Bernard's discovery of "the glycogenic function of the 

 liver". While older physiologists had been more or 



