CHEMICAL PHYSIOLOGY. 35 



the liver employs the sodium as the principal mineral 

 base for its peculiar acids. But an explanation of this 

 strict separation has yet to be found. We are more 

 confused than enlightened by the discovery of the 

 apparent paradox that fish, living in a medium 

 abounding with sodium salts, should form a bile the 

 mineral base of which is potassium. 



The serum carries nearly the whole of the carbonic 

 acid contained in the blood, particularly when it be- 

 comes venous. This is present in two forms, the one 

 dissolved and removable by the vacuum, the other 

 combined with soda as carbonate and dicarbonate, and 

 dislodged only by acids and boiling. It is also possible 

 that the sodium phosphate attracts a portion of car- 

 bonic acid and holds it in peculiar loose combination. 



The physiology of the gases of the blood, of the 

 oxygen, nitrogen, and carbonic acid contained in its 

 modifications of arterial and venous character, .has 

 lately been improved by the invention of instruments 

 and methods ; but these do not yet satisfy all 

 demands. 



The total quantity of blood contained and circulating 

 in a living man has for many years been greatly over- 

 estimated, owing to fallacious conclusions derived from 

 the practice of bloodletting. The best methods avail- 

 able about ten years ago reduced the quantity to 7' 7 

 per cent, of the weight of the body (Bischoff). But 

 this has to be again reduced, as in these processes the 

 myochrome was not deducted from the hematocrystal- 

 line, by the quantity of which the blood was estimated. 

 Seven per cent, of the weight of the body will probably 



