LECT. I. VITAL PHENOMENA NOT EXPLICABLE. 25 



of hydrogen and oxygen, and which finely divided silver 

 produces on peroxide of hydrogen. 



Cell-life. lought here also to mention a fact of importance 

 which I shall have occasion hereafter to speak of more fully. 

 The cell is certainly the elementary organ, the molecule of 

 organic bodies. We can now by the aid of the pheno- 

 menon of endosmose alone, effected entirely under the 

 dominion of physical forces, explain the mechanism of cell- 

 life ; we can tell how the materials necessary for nutrition 

 are able to penetrate the cell, whilst others are eliminated. 

 We shall go over together an extensive series of physio- 

 logical facts, of which endosmose has furnished the expla- 

 nation. 



Vital Phenomena not completely explicable. We may also 

 add, and we intend to demonstrate the fact to you, that light, 

 heat, and electricity are produced in living beings, by the 

 same physico-chemical actions as those which take place in 

 inorganic bodies, and that they offer the same results. But, 

 with the aid of this knowledge and of these analogies, dare 

 we hope to obtain a complete explanation of all the phe- 

 nomena of living beings? For the present, at least, this 

 would be a vain hope. 



Open an animal, examine its kidneys and its liver, and 

 then ask yourselves by what physical force you can explain 

 how the blood, which is carried to an organ, forms bile and 

 urine. Can we, by having recourse to chemical affinities, 

 however modified, and aided by the peculiar structure of 

 the organs, and even also by the actions of contact, can 

 we, I will not say comprehend, but even obtain a glimpse of 

 the way in which the various organs effect the separation 

 and transformation of the constituent parts of the blood, in 

 which all the organic elements are mixed, partly suspend- 

 ed, partly dissolved, and of which they have need in order 

 to repair their continual losses ? What can we say of the 

 functions of the nerves and generation ? 



