342 J. M. Ordway on Waterglass. 
acid,—and drying in an air bath would give a fall opportumt 
for seek am ower: 4 fails to notice that the sesquisilicate 1t8¢ 
relinquishes a part of its acid in parting with its water. 
hardly do to make the broad statement that bisilicate of soda 
cannot exist at a red heat, when a pure bisilicate made 1n the dry 
and of course cooled down through the “ Giithhitze, 
as 
thing into account, we are warranted in affirming only that when 
dissolved waterglass is rendered anhydrous by exposure 10 : ‘ 
necessary heat, a part of the silica goes over into the passlv 
state. And I find this to be true even when especial pains we 
aken to preclude every source of carbonic acid. The reas” 
remains to be Ganbieuied, Fremy+ found that after the trisilicates 
* Dingler’s Polytech. Journal,—cliii, p. 49. 
t Lisig and has Jahresbericht for 1856, p. 353. 
