54 MEMORIAL SKETCH. 



embodied In a memoir " On the Mutual Relations of the 

 Vital and Physical Forces," chiefly written in 1849, and 

 communicated in 1850 to the Royal Society. To this paper 

 Dr. Carpenter looked back in after-years as one of his most 

 original productions. He did not seek in it, he said, "to 

 " increase the knowledge of existing facts, so much as to 

 "develop new relations between those already known." Its 

 main thesis was that what is called " vital force " really 

 has its origin in solar light and heat, not (as generally 

 taught up to that date) in a power inherent in the germ ; 

 that which the germ supplies, according to his views, being 

 the directive agency by which forces derived ab externo are 

 used in the building-up and maintenance of the organism. 

 The paper was at first regarded as too abstract and hypo- 

 thetical, and some doubt was expressed as to its admission 

 into the " Philosophical Transactions." It ultimately ap- 

 peared there in 185 1 ; but it made little impression at the 

 time. Its line of argument, however, secured more and 

 m.ore attention, and its conclusions were finally accepted as 

 a part of the general doctrine of the " Conservation of 

 Energy," which had been previously promulgated by Mayer 

 and Helmholtz, but was not at that time known beyond 

 Germany.* 



V. 



While these speculations were occupying Dr. Carpenter's 

 thought, he was at the same time slowly elaborating a view 



* See the passages from the article entitled, " The Phasis of Force," below, 

 p. 173. In a lecture on " Present Aspects of Physiology " (Edinburgh, 1874), 

 Professor Rutherford said, " Much of the present aspect of physiology is owing 

 " to Ludwig, who introduced into biological study the graphic method of record- 

 " ing movement invented by Thomas Young; to Carpenter, who applied to 

 " pliysiological phenomena Grove's principle of the correlation ol force, and so, 

 " much about the same time as Mayer and independently of him, paved the way 

 " to the application to physiology of Joule and Helmholtz's great principle of 

 " the conservation of energy ; much of it is owing to Du Bois Reymond, on 

 " account of his researches on animal electricity," 



