80 



THE NERVOUS SYSTEM 



without that aid." Many examples have been left 

 out altogether — the work of Boyle, Hunter, 

 Lavoisier, Haldane, Despretz, and Regnault, on 

 animal heat and on respiration ; of Petit, Dupuy, 

 Breschet, and Reid, on the sympathetic system ; of 

 Galvani, Volta, Haller, du Bois-Reymond, and 

 Pfliiger, on muscular contractility : nothing has 

 been said of the work lately done on the suprarenal 

 glands and " adrenalin," and on the blood-pressure 

 in its relation to secretion. For the most part, only 

 those examples have been taken that occur far back 

 in the history of physiology : more has been said 

 about the past than about the present. First, 

 because it was necessary to put an end to the false 

 statements that are made, by those who are opposed 

 to all experiments on animals, about the work done 

 in the past. Next, because the abstruse details of 

 physiology, in the present, are not intelligible for 

 general reading. Next, because it is impossible 

 now to isolate physiology, or to say what belongs 

 to physiology alone, to have back the simpler 

 problems of the past, to discover the circulation 

 of the blood twice. But the experimental method, 

 alike in the past and in the present, has been the 

 chief way of advance. And if a forecast may be 

 made without offence, it is certain that the work 

 of physiology, as in the past and the present, so in 

 the near future, will exercise a profound influence 

 for good on medical and surgical treatment. 

 Among the subjects that especially occupy physi- 

 ologists now are, the more exact localisation and 

 interpretation of the special sense-centres, and the 



