URINE. 153 



" Glutin 1 , vegetable casein, flesh, albumen, fibrin, and the 

 cartilages and bones, contain sulphur in a form quite different 

 from the oxygen-compounds of this substance. This sulphur 

 is separated as sulphuretted hydrogen during the putrefaction 

 of these substances ; it combines with the alkalies, which act 

 powerfully upon these animal substances, and may be obtained 

 from such combinations in the form of sulphuretted hydrogen 

 by means of stronger acids. 



" Now, we know, from the experiments from Wohler, that 

 the soluble sulphurets become oxidized in the organism ; and 

 that thus, for instance, sulphuret of potassium becomes converted 

 into sulphate of potash ; and it is therefore unquestionable that 

 the sulphur of the constituents of the blood, derived from the 

 aliments, or, what comes to the same point, the sulphur of the 

 transformed tissues becomes finally converted into sulphuric 

 acid by the oxygen absorbed in the process of respiration, and 

 thus that in the urine it must appear in the form of sulphates ; 

 and from this cause the original amount of these salts contained 

 in the aliments become increased. The alkaline base which we 

 find in the urine, in combination with this sulphuric acid, is sup- 

 plied by the soluble alkaline phosphates; and the latter, in conse- 

 quence of the loss of part of this base, are converted into acid salts. 



" It follows, from all we have hitherto stated, that the acid 

 nature of the urine of carnivorous animals, as well as that of 

 man, depends upon the nature of the bases partaken of in the 

 aliments, and upon the particular form of their combinations. 

 In the flesh, blood, and other parts of animals, as well as in the 

 grains of the cereal and leguminous plants, there exists no free 

 alkali. The alkali which these substances contain is invariably 

 combined with phosphoric acid : the acids formed in the or- 

 ganism by the vital process, namely, sulphuric acid, hippuric 

 acid, and uric acid, share the alkali amongst them, and this, of 

 course, must give rise to the liberation of a certain amount of 

 phosphoric acid, or what comes to the same point, to the for- 

 mation of a certain amount of acid phosphates of soda, lime, 

 and magnesia. The proportional amount of the liberated phos- 

 phoric acid varies with the temperature ; at a higher tempera- 



1 Dietrich (in the laboratory of Giessen) has examined glutin with regard to its 

 amount of sulphur ; he found wheat-gluten to contain from 0-033 per cent, to 0-035 

 per cent, of sulphur, exactly the same proportion as is contained in albumen or fibrin. 



