66 



saturation with 

 potash. 



Contains com- 

 mon salt, very 

 little phos- 

 phate of lime, 

 oxide of iron ,& 

 animal matter, 

 and an acid. 



This probably 

 the acetous. 



Yet it might be 

 a new acid. 



Positive proof 

 to be sought 

 where practi- 

 cable. 



Th one/id ob- 

 tained se- 

 parate. 



fa properties; 



ON SWEAT AND ITS ACII*. 



been saturated with potash, this base was obtained in the 

 state of carbonate, beside the preceding matters, in the black 

 substance remaining. 



These trials already convinced me, that sweat contains 

 muriate of soda, traces of phosphate of lime and oxide of 

 iron, very little animal matter, no sulphate, no soluble phos- 

 phate, and in addition an acid, the nature of which I already 

 suspected. 



In fact this acid, combined with a base, giving rise to st 

 carbonate by its calcination, must belong to the vegetable or 

 animal kingdom ; and as besides it was volatile, and formed 

 soluble salts with the different salifiable bases, it became 

 very probable that it was the acetous acid. 



Led by this reasoning to suppose the existence of acetous- 

 acid in sweat, I still required possitive experiments, to con- 

 vince myself of it: for though the properties I have menti- 

 oned belong only to the acetous, of all the known acids, yet 

 they might equally belong to an unknown acid. Thus azote 

 is far from being sufficiently characterised by the properties* 

 with which we usually content ourselves as denoting its pre- 

 sence ; namely, it^being without smell, without colour, and 

 without action on blue colours or solution of lime; all nega- 

 tive properties, and far from being as characteristic as those, 

 which, being founded on combinations, maybe termed posi- 

 tive. Farther, to give certainty, there must be a combina- 

 tion of these positive properties, unless some one, which hap- 

 pens in certain instances, be so decisive, as to suffice of 

 itself. 



Thus, though every thing apparently tended to show me, 

 that the acid of sweat was the acetous, it was neceffary for 

 me to obtain it separate, and combine it with different sub- 

 stances, before I would pronounce definitively on its nature. 

 This I effected easily, by distilling with another acid the re- 

 siduum, tvhich a certain quantity of sweat collected in a flan- 

 nel waistcoat slightly alkaline afforded by evaporation. In 

 this distillation I preferred the phosphoric acid ; on one hand, 

 because it is fixed ; and on the other, because as it is very difi- 

 cult to decompose, it acts less on organic matters than many 

 others. I farther took every precaution, to condense the 

 product of distillation in the receiver. This product strongly 



reddened 



