478 Prof. Liebig on the Constitution of 



cess of the kidneys, in the healthy organism, is of the highest 

 importance for the curing of diseases. 



I believe that there is now required only a small number 

 of good and correct observations to establish a fixed rule for 

 the remedies necessary in various cases. Future properly- 

 directed experiments will prove whether sanguification is ab- 

 solutely dependent upon the presence of alkaline phosphates 

 or not; we shall be able to determine whether weak solutions 

 of alkaline phosphates are not the best solvents for uric acid 

 deposited in the bladder; and likewise what is the influence 

 which aliments rich in sulphur, such as mustard, for instance, 

 exercise upon the separation of uric acid in the bladder, in 

 consequence of the formation of sulphuric acid. At any rate, 

 we may, by a judiciously selected diet, alter with positive cer- 

 tainty, and at pleasure, the nature of the urine; we may, 

 without causing any injury to health, keep it alkaline for a 

 long time by adopting a vegetable diet; and this is certainly 

 the first condition necessary to ensure the entire prevention of 

 the formation of uric acid, as is the case with the herbivorous 

 animals. By its combination with an alkaline base, uric acid 

 must in the organism resolve itself into its ultimate ox3'gen 

 compounds with the same facility as other organic acids, if 

 the physician prohibits all substances to be taken as food 

 which, like wine or fat, take possession of the oxygen neces- 

 sary for the transformation of uric acid into carbonic acid and 

 urea. 



The carbonated alkali in the urine of herbivorous animals 

 is separated from the blood by the kidneys ; the urine derives 

 it from the blood ; it is certain, therefore, if we examine the 

 blood one hour or a few hours after the animal has partaken 

 of food, we must find in it this alkali in the same state as it is 

 found in the urine, and that at other periods of the day the 

 ashes of the blood may not contain the least trace of free 

 alkali. But the free alkali does not cooperate in the vital 

 process in the animal organism ; or, if it is necessary in this 

 process, the part which it has to perform may be undertaken 

 with the very same effect by the bibasic and tribasic alkaline 

 phosphates. 



In like manner, when we are contemplating the presence of 

 hydrochloric acid in the gastric juice, we must remember that 

 the alkaline bases, soda, potash, lime, magnesia, are present 

 in the aliments whilst in their natural state, invariably in the 

 form of salts; that is, in combination with phosphoric acid or 

 with organic acids. When, therefore, in the digestive process, 

 hydrochloric acid is supplied by the gastric juice, the first ac- 

 tion of this acid is confined to the decomposition of these salts; 



