VOL. LXXXVIII.] PHILOSOPHICAL TRANSACTIONS. 259 



The 3d portion being boiled with lime water, very little more seemed to be dissolved 

 than in pure water. The 4th portion being boiled with 4 grs. of sub-phosphate of 

 lime, or calcined bone, no more seemed to be dissolved on account of this ad- 

 dition. Nor was more dissolved in the 5th portion, by the addition of 4 grs. of 

 phosphate of lime, made by dropping phosphoric acid into lime water. And the 

 result was the same with the 6th portion, to which were added 4 grs. of super- 

 phosphate of lime, made by adding phosphoric acid to lime water, so as just to 

 make a clear solution, and then evaporating the solution. 



9. Urine seemed to dissolve, or at least to suspend, a greater quantity of the 

 precipitate than mere water; so likewise did water with a little sulphate of soda. 



10. The precipitate did not render solution of hard soap at all curdy; but, on 

 adding the precipitate to solution of sulphuret of pot-ash, it became very turbid. 



1 1 . The precipitate produced a strong effervescence, even in the cold, with nitric 

 acid, but the fumes were not those of nitrous acid: there was a clear solution, 

 which, on evaporation to dryness, afforded black matter, surrounded by a pink, or 

 blood red margin. 12. The substance, with sulphuric acid, turned black, and 

 emitted fumes copiously, which were scarcely those of sulphureous acid; and, on 

 evaporation, a black mark only was left. 13. I first digested, and then boiled, in 

 water, the precipitate with prussiate of iron ; but the filtrated liquor afforded no 

 precipitation with sulphate of iron. 



14. Two dr., by measure, of nitric acid, of the specific gravity of 1.35, were 

 poured on 7 grs. of the precipitate. A violent effervescence took place, which was 

 soon succeeded by a complete solution. A few drops of this solution, being eva 

 porated on glass, left a black mark, surrounded by a pink margin. A few drops of 

 nitric acid being evaporated from this residue, nothing but a still less black mark, 

 and a few red spots remained. Nitric acid being added a third time, nothing but a 

 black mark, still smaller, remained; which entirely disappeared, on evaporating 

 this acid from it a 4th time. I found that a few drops of this solution, so diluted 

 that they did not contain the ^-5-, or even a much smaller part, of a grain of the 

 precipitate, on evaporation, left a pink stain on glass. The whole of the rest of 

 the solution was distilled in a very low temperature, so that a drop only fell about 

 every half-minute, till a thick brownish sediment remained, with a red margin. 

 A similar distillation was performed, with the distilled liquor, a 2d time, when 

 there remained a little whitish thick matter. On a 3d distillation, as before, with 

 the distilled liquor, towards the close white fumes arose, and about 4- dr. of liquid, 

 which now remained in the retort, being left to stand, prismatical crystals, decus- 

 sating each other, were formed. They had a sharp taste, but were scarcely sour; 

 were very soluble in the mouth, and evaporated in white fumes, leaving a very 

 slight black stain. 



15. Twenty grains of the precipitate were introduced into a tube, -£• of an inch 

 wide in the bore, sealed by melting at 1 extremity; which extremity was coated, 

 and the tube was fitly bent for retaining sublimate, and collecting gaz. The tem- 



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