CHAP, v.] OF ASSIMILATION AMONGST ANIMALS. 129 



of the oxydation of the anatomical elements, combines itself 

 with alkaline bases ; the oxydation of the proteic substances 

 causes, specially in the nervous tissue, the formation of phos- 

 phoric acid, which combines itself also with the alkaline bases, 

 united with less powerful acids, ete. 



Tribasic phosphate of lime, which is dissolved in the blood, or 

 combined with the albuminoids of this humour, is deposited in a 

 solid state in the bones, the teeth, and the hair. 



There is a remarkable proportion of chlorure of sodium in the 

 blood, and in all the liquids and solids of the economy. Its 

 office is not yet correctly defined, but its presence seems neces- 

 sary. It cannot help figuring in the alimentation of men and 

 animals. Livingstone, during his travels across the African 

 continent, having to live for whole months without animal food 

 and milk, relates that he was seized with a violent desire to eat 

 sea-salt ; he adds, that after thus abstaining from them, animal 

 food and milk had at first, to him, a very salt taste. 



Though there is in the blood a very small quantity of iron, it 

 is a substance absolutely necessary. We have 'seen that it forms 

 part of the haemoglobine of the blood. Its curative office in 

 anaemia is as beneficial as it is well known. 





2. Hydro-carbonized Principles. 



The hydro-carbonized principles, that is to say, specially the 

 1 amyloidal and saccharine substances, seem only to penetrate into 

 the circulation, and consequently the anatomical elements, after 

 having been transformed into dextrine or glycose, in the same 

 way that amongst plants the amylaceous masses are saccharified 

 before being made use of for nutrition. In the blood, and also 

 in the anatomical elements, these ternary substances meet the 

 oxygen, which reduces them, when the oxydation is complete, to 

 water and carbonic acid. This transformation of hydro-carbonized 

 substances leaves no organic residuum, but develops heat, and 

 contributes powerfully to facilitate all the reactions, all the 



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