10 J. M. Orafis on Ethers of Arsenic Acid. 
wards turned out that they were contaminated with minute 
errors of the character described in this article under the head 
“mode of adjusting, &c.” 3rd; the adjustment alluded to hav- 
ing indeed been always made, but not with a sufficient degree 
of care to exclude the last trace of error. 
New York, March 29th, 1870. 
Art. IL—The Ethers of Arsenic Acid and of Arsenious Acid ; 
by J. M. Crarts.* 
Mr. Frrepet and I observed, while aon kan the ethers of 
view to their let but I have only succeeded in the case 
of arsenious aci 
d cv: 
ARSENIATE OF ETHYL. 
The first attempts were made to prepare this body by the ac- 
tion of arsenic acid on the silicate of ethyl. The arsenic acid 
was dried by heating it in a current of air, and it was then 
in a glass tube with the silicate of ethyl, and heated in 
an air-bath. After heating 10 hours at 210° centigrade there 
appeared to be no reaction ; on heating 3 hours longer at 230°, 
a considerable quantity of the arsenic acid dissolved and ata 
ittle higher temperature the tube Se ae probably in conse- 
quence of the oxydation of the ether by the arsenic acid. 
In another experiment 20 grams of silicate of ethyl were 
heated with 8 grams of arsenic acid for 6 hours at 220°-230°. 
A gelatinous silicate of ethyl was deposited, and on opening the 
tube about $ litre of a gas having the properties of ethylene was 
evolved. A considerable quantity of common ether was formed, 
and the remainder of the liquid contents of the tube was par- 
* The chemical symbols used have the values which belong to them in the new 
