PHYSIOLOGICAL SIGNIFICANCE OF VITAL FORCE. 765 



sought to know their relations in inorganic nature, and already the 

 evidence is prophetic of wonderful results. 



In physical philosophy, " Stahlism " received its mortal wound at 

 the close of the last century by the experiments of Rumford and Davy, 

 which negated the theory of " caloric " and demonstrated heat to be a 

 " mode of motion." 



This new doctrine, though founded on a demonstrated fact, was 

 not complete until 1850, when Joule, having determined the mechani- 

 cal equivalent of heat and established the law of thermo- dynamics, 

 made possible the classification of facts determined by Young, Mel- 

 loni, Faraday, Liebig, Mayer, Grove, Helmholtz, Carpenter, Tyndall, 

 Henry, and others, which enabled the deduction to be made of the 

 universal laws of the " correlation and conservation of energy." 



In inorganic nature, unity, under law, is an accepted fact, and 

 analysis and synthesis harmonize as to causes and effects ; but in the 

 organic world there are yet many unknown quantities, and the prog- 

 ress in solving the mysteries of life-action is necessarily slow, because 

 of their complex character. 



To some, " vitalism " yet maintains its position in the philosophic 

 realm of organization, and a " vital force," independent of and antago- 

 nistic to physical force, yet presides over the manifestations of organic 

 bodies. This, if true, necessitates " two distinct sciences and two dis- 

 tinct orders in nature," which, though related, are not reciprocal. 

 This view is not in harmony with either chemical, physical, or biologi- 

 cal science of the present day, and stands in direct contradiction to the 

 accepted doctrine of the correlation and conservation of energy. 



Whatever may be the essential nature of the ultimate life-principle 

 with which science has nothing to do it can not be denied that life- 

 phenomena are presented to us only through forms of matter. Mat- 

 ter, or material organization, is, therefore, so far as human knowledge 

 goes, an absolute condition upon which all life-manifestations depend, 

 and to assert, as do the " vitalists," that this vital energy an agency 

 which can not be verified, though dependent upon a material condi- 

 tion for a display of its action is not related to it, but is independent 

 of it and under distinct and antagonistic laws, is an assumption at 

 variance with scientific truth and reason. 



Doubtless one common source of error in the minds of the disciples 

 of " vitalism " is inaccurate definition, confounding, as they do, the 

 scientific meaning of a term with its philosophical or metaphysical 

 significance. Thus, the term " life," when applied to the higher ani- 

 mals, is, to the metaphysical philosopher, often related to, or made 

 synonymous with, the " soul " ; while to the physiologist it refers 

 only to the sum of phenomena arising in organized bodies. If what 

 " can not be explained by chemistry or physics " constitutes the vital 

 functions, then, by simply eliminating the known or non-vital factors, 

 we may easily learn the exact amount of the vital element. 



