PROXIMATE PRINCIPLES IN GENERAL. 63 



water, which may be expelled by evaporation ; second, phosphate 

 and carbonate of lime, which may be extracted by the proper sol- 

 vents ; third, a peculiar animal matter, with which these calcareous 

 salts are in union ; and fourth, various other saline substances, in 

 special proportions. In the muscular tissue, there is chloride of 

 potassium, lactic acid, water, salts, albumen, and an animal matter 

 termed musculine. The difference in consistency between the solids 

 and fluids does not, therefore, indicate any radical difference in their 

 constitution. Both are equally made up of proximate principles, 

 mingled together in, various proportions. 



It is important to understand, however, exactly what are proxi- 

 mate principles, and what are not such ; for since these principles 

 are extracted from the animal solids and fluids, and separated from 

 each other by the help of certain chemical manipulations, such as 

 evaporation, solution, crystallization, and the like, it might be sup- 

 posed that every substance which could be extracted from an organ- 

 ized solid or fluid, by chemical means, should be considered as a 

 proximate principle. That, however, is not the case. A proximate 

 principle is properly denned to be any substance, whether simple or 

 compound, chemically speaking, which exists, under its own form, in the 

 animal solid or fluid, and which can be extracted by means which do 

 not alter or destroy its chemical properties. Phosphate of lime, for 

 example, is a proximate principle of bone, but phosphoric acid is 

 not so, since it does not exist as such in the bony tissue, but is 

 produced only by the decomposition of the calcareous salt ; still 

 less phosphorus, which is obtained only bv the decomposition of 

 the phosphoric acid. 



Proximate principles may, in fact, be said to exist in all solids or 

 fluids of mixed composition, and may be extracted from them by 

 the same means as in the case of the animal tissues or secretions. 

 Thus, in a watery solution of sugar, we have two proximate prin- 

 ciples, viz : first, the water, and second, the sugar. The water may 

 be separated by evaporation and condensation, after which the 

 sugar remains behind, in a crystalline form. These two substances 

 have, therefore, been simply separated from each other by the pro- 

 cess of evaporation. They have not been decomposed, nor their 

 chemical properties altered. On the other hand, the oxygen and 

 hydrogen of the water were not proximate principles of the original 

 solution, and did not exist in it under their own forms, but only in 

 a state of combination ; forming, in this condition, a fluid substance 

 (water), endowed with sensible properties entirely different from 



