148 THE SECRETIONS: 



" The alkaline reaction of the lymph, chyle, and blood of 

 man, and of the carnivorous animals, cannot be owing to the 

 presence of a free alkali ; for the nutriment of man, and of the 

 carnivorous as well as the graminivorous animals, contains no 

 free alkali, nor any salt formed of an alkaline base and an acid 

 which might be destroyed in the organism, by the vital pro- 

 cess, and thus cause the alkaline base to be liberated. The 

 blood must contain the same salts as exist in the aliments. With 

 the exception of common salt, nothing is added during the di- 

 gestion of the aliments. We have seen that this substance 

 undergoes decomposition in the upper part of the digestive ap- 

 paratus, being resolved into free soda and free hydrochloric 

 acid ; but we have also seen that the liberated soda rejoins the 

 hydrochloric acid during the preparation of the chyme, and 

 previous to the transformation of the latter into chyle ; x that is, 

 when the acid has performed its function, namely, the solution 

 of the aliments ; the salt formed by this combination, that is, 

 common salt, has neither an acid nor an alkaline reaction. 

 The salts with an alkaline reaction contained in meat, flour, 

 or grain, are alkaline phosphates. Hence it is obvious that the 

 alkaline reaction of the chyle, lymph, and blood of animals feed- 

 ing upon animal and vegetable substances, can only be derived 

 from their alkaline phosphates. 



" The bibasic phosphates of soda and of potash are, in many 

 respects, highly remarkable salts ; although of a tolerably strong 

 alkaline reaction, yet they exercise no destructive action upon 

 the skin or upon organic formations ; they possess all the pro- 

 perties of the free alkalies without being such; thus, for in- 

 stance, they absorb a large amount of carbonic acid, and this 

 in such a manner that acids produce effervescence in a satu- 

 rated solution of this kind, just as they would in alkaline car- 

 bonates ; they dissolve coagulated casein, as well as coagulated 

 albumen, into clear fluids, with the greatest facility, just as 

 caustic or carbonated alkalies do. But of still greater im- 

 portance in relation to the secretion of urine is their deport- 

 ment towards hippuric and uric acids. Hippuric acid dis- 

 solves with the greatest facility in water to which common 

 phosphate of soda has been added ; uric acid possesses the same 



1 Liebig's Animal Chemistry, 2d edit. p. 112. 



