r^ 



i6 



THE BEGINNINGS OF LIFE. 



more 



AH that we have that is good and safe, as the steam- 

 engine, the electric telegraph, &:c., witness to that 

 principle. It would require a perpetual motion, a fire 

 without heat, heat without a source, action without 

 reaction, cause without effect, or effect without a cause, 

 to displace it from its rank as a law of nature.' The 

 time, therefore, must come when the really funda- 

 mental doctrine of the persistence or indestructibility 

 of Force will be recognized by all educated persons 

 to have an equal validity with the secondary, though 



familiar, doctrine of the indestructibility of 

 Matter. The two doctrines are correlatives, and the 

 admission of one implies the truth of the other as a 



necessary consequence. . • 



Having come to an understanding as to what views 

 we are to take of Force and of the mutual relations 

 of the several physical forces, we now have to enquire ^ 

 as to the relation in which these stand to the so-called 

 « vital forces ' manifested by Living Organism?. 

 The first reaP step in explanation was taken in 



1 In an 'Inaugural Address,' delivered in 1868 at the Jeafferson 

 Medical College, U.S., by Dr. J. Aitken Meigs, he claims the credit for . 

 Dr. Metcalfe of having initiated this part of the doctrine. These 

 claims, and also others concerning Lardner Vanuxem, have been con- 

 sidered in the 'British Medical Journal,' January 16, 1869, p. 5°- ^'■• 

 Metcalfe's work, published two years earlier, in 1843, was entitled, 'On 

 Caloric ; its I^echanical, Chemical, and Vital Agencies in the Pheno- 

 mena of Nature.' Dr. Metcalfe seems to have been a man of much 

 power and originality, though he still looked upon heat as a materia 

 substance, an elastic fluid named cnloric. This view, of course, vitiates 

 his treatment of the subject, though it seems clear, from the passage 



Which had bee 

 electricity by 

 nervous power 

 known depend 

 body on the h 

 source of all 

 grees and var. 

 ferred to modi 

 organization 



*li we subjoin, 

 Section. 'AH ti 

 of nature, are attei 

 P™«ss of fennent: 

 ^;^°">Positions an 

 *i«u or subtra, 

 *'^^ b^^'ns, the vi 



. ^^'"^^ f her 



^OL. 



I. 



