CHAPTER I 



THE CORRELATION OF VITAL AND PHYSICAL FORCES 



NEAR the close of the eighteenth century (1798), Benjamin 

 Thomson, afterwards Count Rumford, announced to the 

 Royal Society his conviction, based upon experimental evidence, 

 that " heat was a mode of motion." This conception was the germ 

 of the important doctrine known as " The Correlation of the 

 Physical Forces" enunciated in 1842 by Grove in this country 

 and almost simultaneously by Meyer a physician at Heilbronn — a 

 doctrine according to which heat, light, electricity, magnetism and 

 chemical affinity (the so-called imponderables) were at once con- 

 vertible and indestructible — and all capable of arising from or 

 giving origin to motion either directly or indirectly. In succeeding 

 years this doctrine was developed by many other workers, the most 

 prominent of them being Joule, Clausius, Rankine, Thomson (now 

 Lord Kelvin) and Helmholtz. 



The speculations of ancient philosophers, such as Democritus, 

 Epicurus, Lucretius, and others to the effect that life could be 

 resolved into a series of physico-chemical phenomena, now began 

 to be looked at from a more positive basis. The first real step in 

 this direction was taken in 1845 by Meyer of Heilbronn in a 

 memoir on " Organic Movement in Relation to Material Changes," 

 in which he showed that the processes taking place in living 

 organisms, animal or vegetal, were produced by forces acting upon 

 them from without, and that the changes in their composition 

 brought about by these external agencies were the immediate 

 sources of those modes of force apparently generated in the 

 organisms themselves. A few years later this view was elaborated 

 by Dr. Carpenter in a memoir published in the Philosophical 

 Transactions, " On the Mutual Relations of the Vital and Physical 

 Forces," in which he sought to show " that so close a mutual 

 relationship exists between all the vital forces, that they may be 

 legitimately regarded as modes of one and the same force." He 



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