206 Dr. Carpenter^ on the Relation [Feb. 24, 



WEEKLY EVENING MEETING, 



Friday, February 24, 1860. 



Sib Henby Holland, Bart. M.D. F.R.S. Vice-President, 

 in the Chair. 



William B. Carpenter, M.D. F.E.S. F.G.S. F.L.S. 

 On the Relation of the Vital to the Physical Forces. 



In every period of the history of Physiology, attempts have been made 

 to identify all the forces acting in the living body with those operating 

 in the inorganic universe. Because muscular force, when brought to 

 bear on the bones, moves them according to the mechanical laws of 

 lever-action, and because the propulsive power of the heart drives the 

 blood through the vessels according to the rules of hydraulics, it has 

 been imagined that the movements of living bodies may be explained on 

 physical principles ; — the most important consideration of all, namely, 

 the source of that contractile power which the living muscle possesses, 

 but which the dead muscle (though having the same chemical composi- 

 tion) is^ utterly incapable of exerting, being altogether left out of view. 

 So, again, because the digestive process, whereby food is reduced to a 

 fit state for absorption, as well as the formation of various products of 

 the decomposition that is continually taking place in the living body, 

 may be imitated in the laboratory of the chemist ; it has been supposed 

 that the appropriation of the nutriment to the production of the living 

 organized tissues of which the several parts of the body are composed, 

 is to be regarded as a chemical action ; — as if any combination of 

 albumen and gelatine, fat and starch, salt and bone-earth, could make 

 a living man, without the constructive agency inherent in the germ 

 from which his fabric is evolved. 



A scarcely less unphilosophical method has been pursued by 

 another class of reasoners, who have cut the knot which they could not 

 untie, by attributing all the actions of living bodies for which physics 

 and chemistry cannot account, to a hypothetical " vital principle " ; a 

 shadowy agency, that does everything in its own way, but refuses to be 

 made the subject of scientific examination ; like the electricity or the 

 spiritual power, to which the lovers of the marvellous are so fond of 

 attributing the mysterious movements of turning and tilting tables. 



A decided advance has been made in Physiology, however, by the 

 introduction of the dynamical ideas^furnished by physics and chemistry. 



