Domain of Physiology. 245 



and the same." Helmholtz, from whom I here quote, adds : — 

 " I think the facts leave no doubt that the very mightiest 

 among the chemical forces are of electrical origin ; . . . but I 

 do not suppose that other molecular forces are excluded, 

 working directly from atom to atom"*. 



The activities which appear in dynamic and in chemic 

 phenomena are one in essence; for force is one. The same 

 is true of the activities manifested in organic growth, and 

 even in thought; but the unity and mutual convertibility 

 of different manifestations of force afford no ground for con- 

 founding, as some would do, dynamics with enemies, or with 

 vital or mental processes. All of these phenomena are but 

 the evidences of universal animation, or, in other words, of 

 an energy which is inherent in matter, the manifestations of 

 which, as matter rises to higher stages of development, become 

 more complex, as organic individuals are themselves more com- 

 plex than mineral forms. 



§ 21. From the process which generates chemical species 

 we pass to that which gives rise to organized individuals, in 

 which appear a new class of phenomena, distinguished alike 

 from those of dynamics and those of chemism. These new 

 manifestations, which are called vital, involve dynamical and 

 chemical activities, but display, in addition to these, still 

 higher ones. Matter on this more elevated plane not only 

 becomes individualized, but adapts itself to external condi- 

 tions by organization, and exhibits in the resulting forms the 

 power of growth by assimilation and of reproduction. The 

 study of these forms in all their relations is the object of 

 Biology. Organogeny, or the process of morphological 

 growth and development, distinguishes the biological from 

 the mineralogical individual. The activities of the crystal are 

 purely dynamic ; and its crystalline individuality must be de- 

 stroyed before it can become the subject even of chemism; 

 while the plant and the animal exhibit not only dynamical 

 and chemical, but organogenic activities, which last are desig- 

 nated as vital phenomena. The study of these constitutes a 

 third division of physics, which may be conveniently desig- 

 nated as Biotics (from ftioTiKo?, pertaining to life), and have, 

 to do with organic growth, development, and reproduction 

 — activities which do not appear in the mineral kingdom. 



Mineralogy is the science of inorganic matter, and studies 

 its dynamical and chemical relations; while Biology, which 

 is the science of organic matter, adds to these the study of 

 biotic relations. The dynamic and chemic activities which 



* Helmholtz, The Faraday Lecture, April 5, 1881 ; abstract prepared 

 by its author, ' Nature/ vol. xxiii. p. 589. 



