gr.
1.15, is then added, and the solution distilled, when the whole of the hydrocyanic acid passes over, and by being conducted into a solution of potassa, as in the former process, forms cyanuret of potassium.

This process, though easier than the first described, is rather given as a resource under peculiar circumstances than as one to be adopted by the large manufacturer.

The expense is the only objection, but in a small quantity this cannot be a consideration.
"In giving this very rough outline of the general mode of forming salts, the minutiae necessary for chemical work have altogether been avoided, and those parts alone are entered upon which are more immediately necessary for the electro metallurgist to know and practice for himself.

This will account for the long description of the cyanuret of potassium, while the preparation of the equally important and even more used acids, the sulphuric, muriatic, etc., commonly found in commerce, are altogether neglected.
"In using solutions of cyanide of potassium, the workman should not immerse his arms into them, otherwise it occasionally happens that the solution produces very troublesome eruptions over the skin." HYPOSULPHITE OF SODA.
Hyposulphite of Soda .-- This salt forms one of the important chemicals for the Daguerreotype operator.

Its application to this art is of an interesting nature.