150 Scientific 
Glass treated with 
Experi- 
ment. 
1 | Weak baryta solution, 
2 | Stronger ,, ‘ 
3 | Both baryta solutions, 
Proceedings, Royal Dublin Society. 
Al,O3 Alkaline 
SiO,. and CaO. sul- Remarks. 
Fe,O3. phates. 
Dissolved by the 
0:0045 | 0:0009 | None. 0:0024 
! baryta solution. 
0:0094 | 0:0012 | None. 0:0009 
baryta solution, but 
soluble in weak 
hydrochloric acid. 
Insoluble in the 
0:0008 | 0:0003 | 0-0017 | 0-0014 | 
Alkalies 
as Na.O. 
Percentage composi- : é : : 
tion of the glass, } ie ae iin se 
Although from the minuteness of the quantities involved the 
results of the determinations are somewhat uncertain, we are of 
opinion that our experiments warrant the following conclusions : 
(1.) A weak baryta solution acts with relative rapidity on the 
glass of the Winchester quarts (and probably exercises an appre- 
ciable action on most varieties of glass), dissolving silica and 
alkalies, and smaller quantities of alumina and ferric oxide, but no 
lime. 
(2.) A stronger solution dissolves more silica but (ess alkalies, 
about the same amount of alumina and ferric oxide, and also, asin 
the previous case, no lime. 
(3.) The baryta water also exercises another action whereby 
‘substances are produced which adhere to the glass, and are unso- 
luble in the baryta solution. They dissolve (in part at all events) 
in weak hydrochloric acid, and the resulting solution contains a 
small quantity of silica, practically no alumina or ferric oxide, 
but appreciable quantities of lime and alkalies. 
We may mention that Cossa and G. Lavallet found on the 
sides of a glass vessel containing baryta water, and closed for 
twenty-seven years, transparent columnar crystals which when 
analysed gave— 
Per cent. 
$102, Hl A P 18-56 
BaO, C ‘ 5 48°23 
H.20, F : : 82°38 
100°12 
’ Zeitschr. f. Kryst. u. Min., 11., p. 399; also Chem. Soc. Journ. (Abs.), 50 [1886], 
p. 594. 
