Medicine. 277 



lecting and arranging the facts belonging to animal 

 life, and unfolding the influence of morbid associa- 

 tion, which involves the essence of diseases, the 

 author undoubtedly excels all preceding writers. 

 Still, however, his work must be allowed to labour 

 under great faults and radical deficiencies. In 

 many instances he gives the rein to \\\s imagina- 

 tion, and suffers fanciful speculations to usurp the 

 place of facts and legitimate reasoning. His doc- 

 trine of the retrograde action of the absorbents, of 

 %vhich he makes such frequent and important use, 

 in a great many various states of disease, may be 

 mentioned as one of those which seem to want 

 confirmation. And there is reason, indeed, to ap- 

 prehend that errors still more fundamental and es- 

 sential have crept into this vast plan for binding 

 together the scattered facts of medical knowledge, 

 and converging into one point of view the laws of 

 animated nature. That interesting doctrine com- 

 mon to Dr. Brown and Dr. Darwin, that all the 

 phenomena of life are to be explained on the prin- 

 ciple of the excitability or sensorial power beirfg 

 accumulated and expended, in the inverse ratio of 

 stimulation,^ however elegantly it may admit of 

 illustration by the use of heat, light and food, after 

 coldness, darkness and hunger, seems to fail in its 

 application to many morbid states of the system. 

 It appears, on the contrary, often to happen that 

 excitement and excitability arc increased at the 



t The originality of some of the leading doctrines delivered by Dr. Dar- 

 win has been called in (|uestIon, He himself recognizes the coincidence 

 of some of his opinions with those of Dr. Brown ; but contends that he 

 arrived at his conclusions on those subjects by a different train of reasoning 

 from that of the Scottish theorist. He also declares, and asserts that his 

 friends are able to attest, the fact, that the greater part of his work had lain 

 by him tiventy years before its publication. These facts evidently prelude 

 the probability of his being much, if at all, indebted to Dr. Brown'. Dr. 

 Hartley seems to have been the first who, cV-arly and with effect, cm- 

 ployed the principle of association to account for the phenomena of the ani- 

 mal economy. (See Observations on Man.) It is not improbable that Dr. 

 Darwin was indebted to him for some hints in forming his great work. 



