7$ BIOLOGY. [BOOK n. 



Sulphuric Acid 69,32 



Sugar Candy . 26,74 



Barley Sugar 26,21 



Molasses of Cane Sugar 32,55 



Sugar of Starch 25,94 



Gum Arabic 13,24 



Albumine , 3,08 



Furthermore, these colloids, so slow to blend and to be diffused, 

 are easily penetrated by the crystalloids, while their analogues 

 cannot traverse them except by taking, through isomeric modifica- 

 tion, an altogether special state of solubility. For instance, we 

 shall see when speaking of animal digestion that the albuminoidal 

 substances of the elements, in order to pass into the circulatory 

 system, need previously to be transformed into soluble albuminose. 



We must also remember that two substances, incapable of 

 chemical combination, and possessing different degrees of 

 diffusibility, separate to a certain point, when they are put in 

 a blended state, in a diffusion vessel, for then the more diffusible 

 of the two passes out more rapidly than the other. 



The application of the preceding data to nutrition is achieved 

 almost of itself, so to speak. In effect, from the simply physical 

 point of view, organised beings are merely masses of colloidal 

 substances, holding in solution crystalloidal substances. This 

 definition is strictly true for a number of rudimentary organisms, 

 for instance the amoebae and most of the infusoria ; in general, 

 for all those beings, neither vegetal nor animal, of which Haeckel 

 has made his group of monera. It applies even to a number of 

 zoophytes, and also to every histological element of the superior 

 organisms, isolatedly considered. Let us take the small amorphous 

 mass of contractile albuminoid substance which constitutes an 

 amceba, a rhizopod, or monocellular beings such as the Protococcus 

 nivalis, many infusoria, lastly the globules of the blood of the 

 mammifers, and even the cells and fibres, grouped into tissues to 

 form the body of plants and of the superior animals ; we see 



