JSJ3.] Chemical Properties of Animal Fluids. 



. Water 933*00 



Urea 3040 



Sulphate of potass . . . . 3 - 71 



Sulphate of soda 3*16 



Phosphate of soda 2*94 



423 



1000-00 



With regard to the relative proportions of these ingredients, it 

 is very probable they may vary independently of disease. I 

 believe, however, that in urine they are never very different, 

 unless from pathological causes, which materially affect the 

 health. 



I should also observe that in the 17'14 parts of lactic acid, 

 lactate of ammonia, &c. there exists a quantity of water which 

 it is not possible to abstract without the risk of decomposing 

 these substances. The quantity of uric acid always varies accord- 

 ing to the individual, and also in the same individual from 

 different circumstances which have little influence on health. 

 in the above analysis it was determined from urine which be- 

 came turbid throughout during its cooling, and which during its 

 deposition re-cnibled water mixed with clay. 



The earthy phosphates contain much more magnesia (as much 

 as I 1 per cent.) than in the bones or the ashes of blood. Of the 

 cause of this 1 am ignorant ; but I have likewise found much 

 more potass in urine and in milk than in the blood, 



The silex was not detected by the composition of dried urine : 

 for in this way it might have been considered as i constituent of 

 some animal matter dissolved in the urine. I discovered it by 

 treating evaporated urine with alcohol, then with water, and 

 afterwards with muriatic acid, which left the undissolved silex iu 



