258 PHILOSOPHICAL TRANSACTIONS. [ANNO 17Q8. 



being evaporated to dryness, sometimes a pink, and at other times a blood red, or 

 rose-coloured matter was left; which, by further application of fire, became black. 



5. Carbonic acid, digested and shaken with this solution, did not render it turbid. 



6. To the whole of the remaining solution was added diluted sulphuric acid, to sa- 

 turate the alkali. On standing, a copious precipitate took place, from a clear liquid; 

 which precipitate, being washed and dried, was a mass of very light, mica-like, 

 whitish crystals, amounting to 123 grs. It was estimated that the solution used in 

 the experiment I. — 5, would have produced 12 grs., and that the 30 grs. of soap- 

 like matter, (b,) not decompounded, would have yielded about 14 grs. more. 



(e) The precipitate, (d, 6,) 1 . Had no taste, nor smell, and did not dissolve in 

 the mouth. 2. About 1 part of it only dissolved in 800 parts of boiling water; 

 which solution did not redden paper stained with turnsole, nor the solution and 

 tincture of this test; neither did it change turnsole paper, reddened by acid, to a 

 blue colour. On cooling, the greatest part of what had been dissolved was deposi- 

 ted, in a crystallized state, equally on the sides and bottom of the vessel. This 

 crystallized matter had the properties above-mentioned (d.) Boiling water was 

 found to dissolve a much greater proportion of urinary stone, and also of gravel, 

 than of this precipitate. 3. Lye of mild pot-ash, or subcarbonate of pot-ash, being 

 dropped into the solution (e, 2,) with its crystallized deposit, the crystals at first 

 seemed to dissolve; but, on standing, a great part of the matter was deposited, 

 and the liquid remained turbid. 4. The precipitate being boiled with lye of car- 

 bonate of soda, more seemed to be dissolved than in pure water; but the solution 

 was not clear, and, on evaporating it nearly to dryness, and pouring cold water on 

 it, on a paper strainer, scarcely any thing but the soda passed through with the 

 water; the precipitate remaining behind on the paper. The result was the same, 

 when this experiment was made with a lye of carbonate of ammonia. The result was 

 also the same, with water in which red oxide of mercury had been boiled; which 

 was also boiled with this precipitate, and filtrated after cooling. 5. A little of the 

 precipitate being triturated with quick-lime, hot water was poured on it. The fil- 

 trated liquor gave the precipitate back again, on adding muriatic acid. 6. The 

 precipitate exposed to flame, with the blow-pipe, turned black, emitted the smell 

 of burning animal matter, and evaporated or burnt away without any signs of 

 fusion ; staining the platina spoon black. 7« Five grains of the precipitate, in 4. oz. 

 of water, were left to stand in a warm room, during the months of August and 

 Sept. last, without any signs of putrefaction appearing, or any obvious change 

 taking place. 8. Twenty-four oz. of boiling water were saturated with the pre- 

 cipitate, and divided into 6 portions; from each of which, on cooling, most of it 

 again precipitated. The first portion, on boiling with a little lye of carbonate of 

 soda, the pneumatic apparatus being affixed, discharged no carbonic acid into lime 

 water; but a transparent solution was produced, and on cooling very little was pre- 

 cipitated. The 2d portion was, in the same manner, boiled in a little lye of caustic 

 soda; which gave a transparent solution on cooling, without any precipitation. 



