Physiology of Animals. 55 



by Albrecht von Haller (1708-1777) in his Elementa 

 Physiologic^ Corporis Humani. Educated under Boerhave 

 of Leyden, he became professor at Gottingen in 1736, 

 and for seventeen years taught anatomy, botany, medi- 

 cine, and surgery. 



Prof. W. Rutherford characterizes Haller's position 

 in a sentence: "Possessed of a strictly logical mind, 

 strongly inclined towards physics and mathematics, he 

 insisted on eliminating from physiology all statements 

 that could not be verified by observation and experi- 

 ment ; he added considerably to the store of physiologi- 

 cal facts, arranged them in the logical order of science, 

 and thus gave to physiology its present aspect". 



We may regard the publication of Haller's great work 

 as marking the date when physiology came of age as a 

 specialism. Haller is also of historical interest for his 

 early researches on respiratory movements, the con- 

 tractility of muscle, the irritability of nerves, and many 

 other problems, and for the authority which he lent to 

 two doctrines the Preformation-theory of Development, 

 and the theory of a Special Vital Force, which, in their 

 cruder forms at least, were erroneous and disastrous. 



Among the many noteworthy advances which mark 

 Haller's period, we may select two. The study of irri- 

 tability, which Francis Glisson (1597-1677) had begun 

 almost a hundred years before, was continued by 

 Haller, by John Brown (1735-1788), by Galvani (1737- 

 1798), who discovered animal electricity, and so one 

 gradually passes to Sir Charles Bell (1774-1842), who 

 distinguished the sensory and motor (or afferent and 

 efferent) functions of the dorsal and ventral roots of 

 the spinal nerves, and to Marshall Hall's elucidation 

 of nervous reflex action, which brings us close to the 

 work of to-day. 



On another line, however, there were no less momen- 

 tous steps of progress. The discovery of oxygen by 

 Priestley (1733-1804) and Lavoisier (1743-1794) led 

 Girtannier (1760-1800), Black, and Mayow to sound 

 views on the chemical nature of respiration, and thus 

 one of the Trveu/mra (spirits) of the old physiologists 

 became at length objective and measurable. 



