WITH THE MICROSCOPE. 323 



be readily removed. Fig. 370, pi. LVIII, will give an idea of the 

 changes which take place during the process above referred to. 



OF VITAL POWER. 



38?. of Life. The rital processes of growth, formation, and 

 multiplication never occur unless germinal matter with its marvellous 

 vital power is present. The formed material may be regarded as a 

 product resulting from the collision of internal vital, and external 

 physical forces. It, therefore, owes its. properties partly to the changes 

 occurring in the matter when in the living state, partly to the external 

 conditions present when the matter was undergoing change, that is 

 at the moment of its death. 



I have tried to account for, by physics and chemistry, the 

 changes which take place in the living or germinal matter, as far as 

 can be ascertained by microscopical observation, but like all who 

 have hitherto attempted to explain vital phenomena in this way, have 

 signally failed. I have therefore framed an hypothesis in the hope 

 that it may aid me in attempting to account for the facts. I suppose 

 that a peculiar agency or force compels matter to assume temporarily 

 the peculiar state characteristic of all living germinal matter, but of 

 living matter alone (according to my definition). I venture to call 

 this rital power. Although in the present state of our knowledge 

 we can perhaps form no positive conception of the real nature of 

 this wonderful power, any more than can be formed of the nature of 

 gravitation, heat or electricity ; by studying the phenomena we gain, 

 it seems to me, very strong arguments against the view now very pre- 

 valent that vital power is but a peculiar mode or form of ordinary- 

 force, or corresponds to what we call the peculiar property of each 

 different inorganic substance, by virtue of which it exhibits a con- 

 stant crystalline form, a definite specific gravity, manifests a certain 

 characteristic behaviour towards other substances, &c. Vital power, 

 it is true, is only manifested under certain conditions which are 

 fixed and definite, though very different for different living things ; but 

 is it necessarily a result of the influence of those conditions on inor- 

 ganic matter ? We are unacquainted with all the conditions absolutely 

 necessary to life ; but is it not almost certain that the external con- 

 ditions, whatever they may be, might exist for any period without 

 any form of life whatever being manifested ? 



Some will say, vital power must be another mode or form of 

 ordinary motion, because there is nothing else in nature that it can 

 be. There is, it will be said, but one power capable of giving rise 

 to the phenomena we term rital, and this is force of some kind or 



Y 2 



