THE DEEPENING OF PHYSIOLOGY. 323 



complicated form of motion regulated solely by the 

 laws which govern inorganic nature." * 



What has been achieved is a detection of chemical 

 and physical sequences in vital phenomena, what has 

 not been achieved as yet is a redescription of a 

 vital phenomenon in terms of chemistry and phys- 

 ics. Prof. J. T. Wilson states the case in an able 

 address : f — ^' I shall not dispute the proposition 

 that, in the progress of the science of physiology, 

 physico-chemical theories of living processes have 

 broken down all along the line. I readily admit that 

 such theories have in every direction failed to accom- 

 plish that mechanical analysis of function which 

 seemed to the physiologists of the later decades of 

 the century to be so nearly within their grasp. Yet 

 it would be grossly inaccurate to assert that the at- 

 tempt to explain life as mechanism has resulted in 

 nothing but failure. The fact is that mechanism 

 after mechanism has been displayed, through the 

 operation of whose chemical and physical properties 

 the functional activity of the organism is subserved. 

 On the other hand, it is true that the residual phe- 

 nomena unexplained by these mechanisms may in a 

 sense be held to embody the very essence of the 

 mystery of organisation. It is not difficult to see 

 that in the nature of the case this must be so. It is 

 the penalty of the abstract character of the causal 

 principle employed as the instrument of research. 

 The forging of links in an endless chain of mechan- 

 ical causation is a never-ending process, — the mys- 



* G. Bunge, Text-hook of Physiological and Pathological 

 Chemistry, trans, by L. C. Wooldridge; London, 1890, p. 3. 

 The quotation expresses the reverse of Bunge's own posi- 

 tion. 



t President's Address, Proc. Linncean Soc. N. 8. Wales 

 XXIV., 1899, pp. 1-29. 



