210 Comparative Physiology. 



may be difficult to decide ; perhaps we liave no means of deciding ; 

 but it is safest to adopt that which is farthest removed from 

 accident. 



In Chap. I., he says : " vitality is not a subordinate principle 

 presiding over matter, but a property impressed on the or- 

 ganised structure by its Creator ; a property of organised beings, 

 as electricity of inorganic, or as gravitation is of systems. It is 

 more consonant to Divine Wisdom to suppose it impresses laws 

 on matter, than to suppose it to delegate the control of matter 

 to a secondary psychological being. Vitality is a law im- 

 pressed on form, by which it works, rather than a power 

 deputed to a secondary power. The truth appears to lie be- 

 tween the extremes of those who attribute all the actions of 

 living beings to vitality, and those who maintain that they are 

 purely of a physical nature. Dr. Herschel says that the Divine 

 Creator of the universe has, by creating his materials endowed 

 with certain fixed qualities and powers, impressed them with the 

 spirit, not the letter, of his law, and made all their subsequent com- 

 binations and relations inevitable consequences of this first im- 

 pression. Our belief of the uniformity of nature proceeds from 

 our conviction of the immutability of the Deity. To suppose 

 that alterations would be required would be to deny the per- 

 fection of the divine attributes ; while to say that the properties 

 first impressed on matter would of themselves continue its 

 action, would be to deny our dependence on the Creator." 



" It is not logically correct to speak of vital properties as su- 

 peradded to organised matter. Organisation and vital proper- 

 ties are simultaneously communicated to the germ l3y the 

 structure of its parent. As we have no evidence of the exist- 

 ence of vital properties, unless in organised matter, so we 

 have no reason to suppose that organised matter can retain its 

 regular constitution, and be subjected to its appropriate stimuli, 

 without exhibiting vital actions. Vitality is not a cause of 

 vital action, but the character of the being which exhibits such 

 action. Death is the separation of that bond of union which 

 unites all the functions of the living system. Molecular death, 

 or the death of parts, is not always the consequence of the 

 general or systemic death. The mere cessation of vital actions, 

 whether apparent or real, does not constitute death. Their 

 suspension may result from the want of stimuli. Seeds may 

 preserve their vitality for a length of time ; it is scarcely cor- 

 rect to say here that the seed is ahve, since life is synonymous 

 with vital action, but it is possessed of vital properties, or 

 vitality, so long as no destructive change takes place in its 

 organisation." 



" In the production of the alimentary materials, of gum, sugar, 

 albumen, gelatine, &c., which are preparations for organisation. 



