168 Friedel and Crafts on the Ethers of Silicic Acid. 
As this ether, which may be named hexethylic disilicic ether, 
was not obtained by Ebelmen, we have used great care in assur- 
ing ourselves, that it is really a distinct compound, and rely as 
proof upon the following facts. The boiling point after repeated 
distillations remains constant at a temperature too remote from 
that of the boiling points, which Ebelmen indicates for the nor- 
mal ether and for his bisilicate, to make it possible to consider 
it as a mixture of these two compounds. We succeeded in ob- 
taining the ether almost pure by treating chlorid of siligium 
with alcohol containing the requisite quantity of water. The 
product of this experiment was distilled under a pressure of 3-5 
mm., and distilled almost entirely at 126°-130°. 
is product, boiling at 126°-130° in vacuo, furnished the ma- 
terial for the determinations of silica vI and vl given above. 
VI. Substance, weight, = - . - - 0°7305 
Gig oe tee ES Cg PS 
VIL. Substance, weight, = - : : - 09370 
Oi. ere Ss bc a RS 
A . 
We thought at first that the compound was decomposed by heat, 
This we satisfied ourselves of by making a determination of si - 
licie acid of the liquid remaining in the bulb. 
I. Substance, weight, - - - -  0:88%5 
Sid, Ba ei ce cena = ORROe 
Si=16°82 instead of 16°88, the theoretical number. If we sup 
iat that the excess of silica came from an admixture of a bod 
aving the composition of the bisilicate of Ebelmen, the liquid 
remaining in the bulb must have contained one-tenth its weight 
of that compound. 
second determination made with a product redistilled seve 
ral times and boiling at 233°-234° gaye 12-025, a number whic 
corresponds very closely with the theoretical 11:86. 
SS 
