252 SELECTED ARTICLES. 
his knowledge ? We know not, but the questions were what 
a first year's student of the Edinburgh school would have 
taken no credit to himself for answering. 
ART. XLVL— RESEARCHES ON THE CHLORIDES AND 
OXIDES OF MERCURY,~By Robert Kane. 
It is a long time since the action of ammonia on corrosive 
sublimate was first noticed, several facts have been establish- 
ed, and all the chemists who have made it their study, have 
arrived at different conclusions, — and each has proposed his 
own theory. A more complete examination of this reaction, 
which might lead to an exact result, was therefore a deside- 
ratum. 
Ammonia acts on corrosive sublimate in two ways. Grou- 
velle and Rose have investigated the action of the gas on the 
dry sublimate, and the papers of Fourcroy, Hennell, Guibourt, 
Soubeiran, and Mitcherlich, on its action in a state of solution, 
show the importance these chemists attach to the subject. 
A solution of ammonia, poured into a solution of sublimate, 
produces a milky precipitate which separates slowly, and 
resembles recently precipitated alumina. If the precipitate 
be thrown from hot solutions, or if it be well washed, it has 
a yellow tint. If, on the contrary, it be boiled in the liquid 
from which it has separated, a very heavy granular powder, 
of a canary yellow, is obtained. 
This white precipitate is insoluble in water. Its apparent 
solubility is owing to its decomposition, or to its elements 
entering into new compounds. Heated in a glass tube closed 
at one end, it is decomposed below a red heat, giving off a 
