ON URINE AND ITS ACIDS* ($J 



te.Mened infusion of litmus: its taste was that of a weak- 

 aeid: its smell that of vinegar: combined with potash it 

 formed a salt, which by evaporation was reduced to little 

 Wiihing scales, micaceous as it were, acrid, and very deli- 

 quescent: on the addition of sulphuric or phosphoric acid 

 this salt evolved a strong smell of acetic acid; and, poured 

 into a solution of nitrate of mercury, it precipitated crystal- 

 line scales, similar to accetite of mercury. 



This acid therefore was the acetous, and consequently hu- This acid the 

 man sweat is formed of a great deal of water f free acetous acetous « 

 acid; muriate of soda; an atom of phosphate of lime and 

 oxide of iron ; and an inappreciable quantity of animal matter, The animal 

 which approaches much nearer to gelatine than to any other S^XunT 

 substance. 



Part. IT. Of the acids of urine. 



These acids are, 1st, the uric acid, which frequently gives Urine contain* 

 Vise to the stone in the bladder: 2dly, thebenzoic acid, which s mtt\mQs 

 exists very rarely in that of adults or old persons, and is benzoic, and a 

 tnore frequent in that of infants : 3dly, we are obliged to ad* thl ' 

 mit another acid, since the urine strongly and constantly 

 reddens tincture of litmus, an action which cannot be 

 ascribed either to the uric acid, that does not alter its colour, 

 i>Y to the benzoic acid, that is found in the urine only un- 

 der certain circumstances, which are not yet well known. 



What is this new acid? This is the second question that I whatisthitj 

 shall attempt to discuss. At present it is generally supposed acid? 

 to be the phosphoric acid. This opinion is grounded on the Supposed to be 

 presence of a pretty large quantity of phosphate of lime in phosphoric. 

 urine, which, being itself insoluble when neutral, becomes 

 very soluble and even deliquescent, when it is with an excess 

 of acid : and at the same time it is strengthened by the con- 

 sideration, that beside the phosphates of lime, soda, amtno- 

 nia, and magnesia, we find nothing in urine but the sulphates 

 of potash and soda, and muriates of soda and ammonia, 

 neither of which salts is decomposed by the acidulous phos- 

 phate of lime: their acids therefore, that is the sulphuric 

 and muriatic, cannot exist in the urine, sine^ as is well 

 known, they would convert the phosphate of lime into aci- 

 dulous phosphate of lime. If then the phosphoric acid be 

 X F 2 not 



