14 Dr. Thomas Thomson putY 



Urate of ammonia 0*298 



Sal-ammoniac 0*459 



Sulphate of potash 2-112 



Chloride of potassium .... 3*674 



Chloride of sodium 15*060 



Phosphate of soda 4*267 



Phosphate of lime .... 0*209 



Acetate of soda 2*770 



Urea with colouring matter . . 23*640 



42-489 



Such, by my analysis, are the constituents of healthy 

 urine of the specific gravity 1*0185. The mucus which may 

 occasionally be seen in it in very minute quantity has been 

 omitted, because it is a secretion of the mucus membranes 

 through which that liquid passes, and does not belong to 

 the urine itself. 



The only other analysis of urine is that of Berzelius, 

 made almost thirty years ago, which differs very much 

 from mine. Berzelius does not give us the specific gravity 

 of the urine which he employed. But certainly it was not 

 healthy urine ; for he states that it became quite turbid on 

 cooling, which healthy urine does not do. 



I have analysed specimens of healthy urine of various 

 specific gravities, from 1*01 to 1*021, and have obtained 

 nearly the same ratios of the constituents as in the pre- 

 ceding analysis. All the individuals whose urine I examined 

 inhabited the west of Scotland. It would be interesting to 

 have the analysis of urine from individuals living in different 

 countries, and supported by different kinds of food, that we 

 might ascertain whether the above ratios be constant, or 

 whether, as is most likely, they would vary with the climate 

 and the food. 



Proust affirms that recently emitted urine contains 

 carbonic acid gas, and that its escape occasions the frothing 

 which always appears during the evaporation of urine. 

 Vogel assures us, that he put a quantity of fresh urine into 

 a phial from which there passed a tube which sunk to the 

 bottom of a vessel filled with lime water. The whole of 

 this apparatus being put under the receiver of an air pump, 

 and the air exhausted, air bubbles rose from the urine, 



