VOL. LXXXVIII.] PHILOSOPHICAL TRANSACTIONS. 257 



calculi were triturated with 3 and 4- oz. by measure, or 5 oz. by weight, of lye of 

 caustic soda. The mixture became thick, and copiously emitted ammoniacal gaz. 

 After digestion for a night, and then boiling, with the addition of 5 oz. of pure 

 water, I obtained, by filtration, 5 oz. of clear colourless liquid. Boiling water was 

 repeatedly poured on the strainer, till what passed through it was almost tasteless, 

 and remained clear, on the addition of diluted sulphuric acid. 



(a) The matter remaining on the strainer, being dried, was an impalpable, white, 

 tasteless, heavy powder, which weighed 96 grs. (b) The 5 oz. of filtrated liquid, 

 having been set apart, on standing, deposited a white, opaque, granulated, soap- 

 like matter, from a colourless clear liquid. The liquid being decanted, the deposit 

 was dried, and was then an opaque, brittle, soap-like matter, which dissolved 

 readily in water, giving a clear but not viscid solution, and tasting weakly of soda. 

 This soap-like matter weighed 280 grs. (c) The decanted liquor (b,) being mixed 

 with the above filtrated liquors, on evaporation to 3 oz. afforded no deposit on 

 standing, though it was a very heavy and soapy liquid to the feel ; but, on adding di- 

 luted sulphuric acid gradually, till it ceased to become turbid, a sediment was de- 

 posited, which was a very light, white, impalpable powder, in weight, when dried, 

 26 grs. The liquid from which this powder was precipitated, being evaporated, 

 afforded nothing but sulphate of soda, and a few grains of crystals, which seemed 

 to be phosphate of soda. There was also a blackish matter, which burnt like 

 horn, or other animal matter, and did not leave a pink or rose-coloured matter, 

 on evaporating the solution of it in nitric acid to dryness, but left a carbona- 

 ceous residue; whereas, the white precipitate, so treated, afforded a beautiful pink 

 matter. 



(d) 250 grs. of the soap-like matter (b) being dissolved in 8 oz. of pure water; 

 1 . A little of this solution, further diluted by 1 oz. of water, grew milky on adding 

 a few drops of nitric acid, but became less so on standing. On adding more nitric 

 acid, and heating it, the mixture became quite clear: by adding a few drops of lye 

 of caustic soda, a very slight curdy appearance took place. 2. On adding, to the 

 same diluted solution, a little of the diluted sulphuric or muriatic acid, milkiness 

 ensued, and remained, though the acids were added till the mixture was extremely 

 sour. On adding lye of caustic soda, much more than to saturate the super- 

 abundant acid, the mixture became clear again ; and, on adding the acids a 2d time, 

 the milkiness was reproduced. It was found that the milkiness could be produced 

 and destroyed, or clearness be produced, by the alternate addition of the acid and 

 alkali, for an unlimited number of times. If the nitric acid however was used, at 

 length no milkiness could be induced. If carbonate of soda was added, instead of 

 the caustic soda, the mixture could not be made clear. 3. Lime water was rendered 

 turbid by this solution, but I neglected to examine the precipitated matter. 4. A 

 little of the solution, with the addition of a few drops of concentrated nitric acid, 



exist in both of them, it can be no objection to the experiments, that I made use of a mixture of 2 

 calculi. — Orig. 



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