Page:Transactions of the Geological Society, 1st series, vol. 1.djvu/231

 the colour of these precipitates was much paler when the water had not previously been exposed to the atmosphere.

I. Alkaline solutions produced copious greenish flocculent precipitates, which became darker on standing in the air.

K. Nitrat of silver occasioned a dense, white, but not considerable precipitate.

L. Both muriat and nitrat of barytes occasioned copious white precipitates.

M. A piece of marble being boiled for some time in a few ounces of the water, the marble was found to have undergone no sensible loss of weight by that operation; but its surface had acquired a faint yellowish tinge.

N. A quantity of the water being evaporated to dryness, and a considerable degree of heat applied to the dry residue, a solution of this in water had the same effect of reddening litmus as before.

§ IV. Inferences arising from those Effects.

1. From experiment A, connected with experiments C, H, I, M and N, and from the circumstance of taste, and other general properties, it appeared highly probable that the water contained sulphat of iron, and perhaps also sulphat of alumine, without any uncombined acid.

2. From experiments C and D, it appeared evident that iron and lime were contained in the water, and that their solvent was not carbonic acid.