Prep. By dissolving one ounce of granulated tin in three fluid ounces of hydrochloric acid, diluted with one fluid ounce of distilled water, with a moderate heat, until gas ceases to be evolved, and subsequently adding sufficient distilled water to make up the bulk to five fluid ounces. The solution, together with the undissolved tin, should be transferred to a well stoppered bottle.

Use. This is a solution of the protochloride of tin (Sn Cl). Protochloride of tin absorbs oxygen and chlorine very readily, and is a powerful deoxidizing agent. It reduces to the metallic state the salts of mercury, silver, gold, etc.; and the solution is often made use of for precipitating mercury from its combinations. It is used in the Pharmacopoeia for this purpose. The ammoniated mercury boiled with the solution of chloride of tin becomes grey, and deposits globules of metallic mercury.