IN THE AN[MAL ORGANISM. 213 



to that of oxygen, the manifestation of which must be 

 considered as dependent on the vital force. 



In chemical language, to annihilate the chemical ac- 

 tion of oxygen, means, to present to it substances, or 

 parts of organs, which are capable of combining with it. 



The action of oxygen (affinity) is either neutralized 

 by means of the elements of organized parts, which 

 combine with it (after the free vital force has been con- 

 ducted away), or else the organ presents to it the pro- 

 ducts of other organs, or certain matters formed from 

 the elements of the food, by the vital activity of certain 

 systems of apparatus. 



It is only the muscular system which, in this sense, 

 produces in itself a resistance to the chemical action 

 of oxygen, and neutralizes it completely. 



The substance of cellular tissue, of membranes, and 

 of the skin, the minutest particles of which are not in 

 immediate contact with arterial blood (with oxygen), 

 are not destined to undergo this change of matter. 

 Whatever changes they may undergo in the vital pro- 

 cess, affect, in all cases, only their surface. 



The gelatinous tissues, mucous membranes, tendons, 

 &c., are not designed to produce mechanical force ; 

 they contain in their substance no conductors of me- 

 chanical effects. But the muscular system is inter- 

 woven with innumerable nerves. The substance of the 

 uterus is in no respect different in chemical composition 

 from the other muscles ; but it is not adapted to the 

 change of matter, to the production of force, and con- 



