190 J. M. Ordway on Watergiass. 
22.—100 g. of 25 p. c. NaSig.s, with 50 g. of 25 p-¢. Nae, gave 41°8 g. 
of a hard pressed product containing 53°4 p. ¢. net of NaSio¢4. 
The mother- <a contained 2 p, c. of NaSi. 
23.—100 g. of 10 p.c. NaSig.s, with 100 g. of 10 p.c c. NaAc, gave 4'8 g. 
‘of a hard er = 5 mass, not wholly soluble in water, and con- 
taining 52 p.c. of NaSig. 
24,—100 g. of 25 p.c - Nai,, with 100 g. of 25 p.c. NaAc, gave 36 g. of 
a hard pressed, soluble precipitate, containing 47 p.c. of NaSias6. 
Acetate of soda gave very slight eee with sesquisili- 
cate of soda, but 2 after standing some 
25.—100 g. of 25 p.c, KSig5, with 100 g. of 30 p.c. KAc, gave 35°4 g- 
of a hard siulied soluble mass, ie ne 61:4 p.c. net of KSigg6. 
The oe showed 1:2 p.c. 
26.—100 g. of 25 p.c. NaSigs, with 100 g. of 25 p.c. nitrate of soda, 
gave 26°5 g. a a hard pressed, soluble EPEREAC containing 24 p.¢. c. of 
mother-liquor and 48-4 p.c. of NaSiog 
In the mother-liquor ihaee were 6°4 a c. of NaSig.oe. 
pales of soda had very little effect on the more alkaline 
* Salptiats of soda has still less precipitating pore than the 
nitrate, as the following example sufficiently shov 
27.—100 g. of 25 p. c. NaSio.5, with 100 g. of 25 p. ¢. ae: underwent 
no change. 100 g. more of the sulphate solution after a time gave 17 
g.of a hard pressed, partially soluble precipitate containing 51°6 p. & 
net of N 
28.—100 ‘ of 25 pc. NaSies, with 100 g. of 25 p.c. hyposnIphite of 
soda, gave 12°6 g. of a hard pressed, soluble precipitate, containing 
29.—100 g. of 25 p.c. NaSig.5, with 100 g. of 25 p. c. tartrate of soda, 
gave Si g. of a hard pressed, soluble curd containing gross 53 p. & 
of Na 
30.—100 g. of 25 p.c. KSigs, with 100 g. of 25 p. c. KOs, gave 7 g.of & 
hard pressed precipitate not wholly soluble in water ve, 
31.—100 g. of 25 p. c, NaSiog abe no precipitate with 100 g., with 2 
g., or with 400 g. of 25 p. c. Nad. 
And in other trials of the carbonate with the same and with 
more alkaline silicates, there was either no deposit at all or an 
exceedingly slight one appeared only after long standing. Nor 
mal carbonate of soda, therefore, is devoid of precipitating 
wer. 
When common arseniate of soda is mixed with a waterglass 
solution, no proper curd is formed at first, but the whole mia 
soon bezomes a very firm translucent jelly, which in the cou c 
of a few days breaks up into a thin liquor and a sort by ae 
lum capable of being pressed. Among many ex periments oe “a 
with 10 or 25 p. c. arseniate solutions and different silicates, 
hard pressed product has in no case proved to be wholly soluble. 
