CHAP, vi.] OF LIVING LIQUIDS. 65 



which remains in the serum with the albumine or serine and 

 can be separated therefrom. That all these determinations of 

 contemporaneous chemistry are destined to be maintained intact 

 in the future we do not believe. 



In effect, the albuminoidal substances are extremely unstable ; 

 those of the economy are probably isomeric, or nearly so. Their 

 chemical formula has not even yet been determined. They are 

 not naturally absorbable, except on condition of being soluble ; 

 the fibrine and the albumine of the aliments are transformed by 

 digestion into isomeric substances called peptones, albuminose, 

 whose degree of relationship with the plasmine and the serine 

 of Denis has not yet been determined. In short, these are 

 questions the precise solution of which must be reserved for the 

 chemistry of the future. 



To conclude what we have to say on the principal organic 

 materials of the blood, let me mention the fine guttulse of fat 

 matter floating in the blood after digestion, in the state of emul- 

 sion. These fat bodies are absorbed by the tissues, which yield 

 them afterwards to the sanguineous liquid, in the state of com- 

 bination, saline, saponaceous, and soluble (butyrates, phosphorised 

 fat matters). Let me mention, lastly, a certain quantity of glucose 

 or sugar of grape. 



The mineral substances dissolved in the blood are not all in 

 the state of simple blending. If we inject into the blood first 

 of all a solution of a salt of iron, then a solution of prussiate 

 of potash, we do not obtain the characteristic reaction of the salts 

 of iron, the formation of Prussian blue, because the albuminoidal 

 substances of the blood have at the very outset fixed the salt of 

 iron. On the contrary, we obtain Prussian blue if we inject 

 first of all the prussiate of potash, because the albuminoidal 

 substances leave this salt free (Claude Bernard). 



5. Of the Red Sanguineous Globules. 



If we examine in the microscope a guttula of blood, we find 

 small floating bodies, extremely numerous, pressed against each 



F 



