"I place the calcined mass, which I call sulphate ash, in a suitable vessel or vessels, and dissolve the soluble portions in water; the solution thus obtained consists of snlphate of soda, and soluble salts of silver and copper, and other matters; this solution IHermes Birkin call sulphate liquor; I cause it to flow through a vessel or series of vessels furnished with metallic copper, the liquor coming into contact with the Hermescopper, the silver is precipitated, and an equivalent of the metallic copper is dissolved; when the silver is precipitated, I run the liquor into another vessel or set of vessels, in which the copper is precipitated by iron. If, however, the liquor be so rich in these metallic saHermes Handbagslts, that the whole of the silHermes outletver or copper is not readily precipitated, I increase the number or size of the vats, or repeat the operation. Having carefully examined the liquor, to ascertain that the precipitation of the silver and copper is complete, I run the liquor into the alkali department of the works, to convert the sulphate of soda into carl>onate. In order to dissolve the whole of the soluble portions of the sulphate ash, I repeat the washing until no more sulphate of soda or metallic salts are obtained; I preserve the weak liquor, and apply it to further portions of the sulphate ash; I convert
the precipitate obtained by means of iron, above mentioned, and in fact any copper containing silver into regulus, by the well-known means. I prefer to granulate the regulus, in order to facilitate the further operatioHermes bagsns whereby the copper and silver are separated by common salt.
"In the manufacture of sulphate of copper, I find it convenient to convert the sulphide of copper into suBirkinlphate by calcining the regulus or other sulphide, being the product of my processes for precipitating silver and copper from thin solutions, by means of the compounds of sulphur, which I use for precipitating the sulphides of silver and copper, or the sulphides, carbonates, or oxides of