44 On the Compofition and Properties 
of foda was added, in place of the cauftic foda, the mixtare 
could not be made clear. 
- 3. Lime water was rendered turbid by this folution, but I 
neglected to examine the precipitated matter. 
4. A little of the folution, with the addition of a few 
drops of concentrated nitric acid, being evaporated to dry- 
nefs, fometimes a pink, and at other times a blood-red, or 
rofe-coloured matter was left; which, by further application 
ef fire, became black. 
5. Carbonic acid, digefted and fhook with this folution, 
did not render it turbid. 
6. To the whole of the remaining folution was added 
diluted fulphuric acid, to faturate the alkali. On ftanding, 
a copious precipitate tock place, from a clear liquid; which 
precipitate, being wafhed and dried, was a mafs of very 
light, mica-like, whitith cryftals, amounting to 123 grains, 
It was eftimated that the folution ufed in the Experi- 
ments I.—5. would have produced 12 grains, and that the 
30 grains of foap-like matter, (4,) not decompounded, 
would have yielded about 14 grains more. 
(e) The precipitate, (d, 6.) 
1. Had no tafte, nor fmell, and did not diffolve in the 
mouth. 
2, About one part of it only diffolved in 800 parts of 
boiling water; which folution did not redden paper ftained 
with turnfole, nor the folution and tin€ture of this teft; 
- meither did it change turnfole paper, reddened by acid, to a 
blue colour. On cooling, the greateft part of what had been 
diffolved was depofited, in a cryftallifed ftate, equally on the 
fides and bottom of the veffel. This cryftallifed matter had 
the properties abovementioned (d). Boiling water was found 
to diffolve a much greater proportion of urinary flone, and alfo 
of gravel, than of this precipitate. 
3. Lye of mild potath, or fubcarbonate of potafh, being 
dropped into the folution (e, 2.) with its cryftallifed depofit, 
the cryftals at firft feemed to diffolve; but, on flanding, a 
great 
