FORMATION OP HYDROCYANIC ACID, ETC. 
115 
The formula assigned by Berzelius to magnesia alba, 
3 (Mg. 0, C 2 ) + Mg. 0, H + 3 H 0. 
does not agree with the analytical results. Reckoned to 
100 parts, it gives 
Magnesia, - 44.57 
Carbonic Acid, - 44.77 
Water, 19.48 
100. 
Mr. Phillips, whose experiments coincide exactly with 
my own, has deduced the formula 
4 (Mg. 0, C 2 ) + Mg. 2 H + 4 H 0. 
which is probably the correct one. 
Ibid. 
ART. XXV11. — ON THE FORMATION OF HYDROCYANIC 
ACID FROM. THE RE- ACTION OF NITRIC ACID ON AL- 
COHOL. By M. Dalpaiz. 
The author having had occasion to prepare some spirit 
of nitric ether according to the process of the London Phar- 
macopoeia, observed that the product afforded a white floc- 
culent precipitate with nitrate of silver, possessing all the 
characters of cyanide of the metal. The formation of hy- 
drocyanic acid under the circumstances was an interesting 
fact; but M. Dalpaiz was not satisfied with having observed 
it: he was anxious to study the influence of varied propor- 
tions of acid and alcohol, and of different degrees of tem- 
perature, upon the phenomena observed. 
He distilled, by the heat of a water-bath, a mixture of 
Rectified spirit, sp. gr. .847, 360 grammes. 
Distilled water, 180 * 
Nitric acid, sp. gr. 1.384, 90 " 
