528 Chemical Physiology and Pathology. 



organism could produce them by a sort of in-dwelling power, 

 are taken up only from the soil. These inorganic substances 

 serve for the production of the vegetable acid salts, which 

 appear to be necessary for certain ends indispensable to the 

 existence of the plant. According to Liebig's researches, 

 they can take each other's places, and a plant, when it cannot 

 find such a base at all, or only in too small a quantity in an 

 assimilable state, either remains backward in its development, 

 or produces an organic base (such as solanine, chinine, 

 morphine, &c.) to take the place of the inorganic bases which 

 are wanting. 



(b. ) Principles of Chemistry in the animal kingdom. (Ac- 

 cording to Mulder, Liebig, Lehmann, &c.) the chief consti- 

 tuent of the animal body is proteine (consisting according to 

 Mulder of carbon 4, hydrogen 31, nitrogen 5, oxygen 12,) 

 which in combination with phosphorus or sulphur, or with 

 both at once, forms the radical of albumen, of fibrine and 

 of caseine. It is therefore the element of the most important 

 phenomena of life, in the course of which it undergoes end- 

 less transformations, and is at last converted into a substance, 

 which is excreted as being of no further use to the body. 



Albumen (which consists of 10 atoms of proteine, 



2 atoms of sulphur, and 1 phosphorus) is in the animal body 

 the commencing point of all nutrition, as well as the primitive 

 form of the other combinations and metamorphoses of pro- 

 teine. It is for the present assumed, that in the process of 

 digestion all the other nutritious substances which contain 

 proteine (fibrine, gum, caseine) both of animal and of vegetable 

 origin, are first converted into the most soluble combination 

 of proteine, before they can pass into the blood, and take a 

 share in the process of nutrition : and that after this, the other 



combinations of proteine are formed from the blood. ■ 



Fibrine (consisting of 10 atoms proteine, 1 atom phos- 

 phorus and 1 sulphur) existing in a fluid state in the blood, 

 and in a coagulated one in the muscles, maintains its com- 





