Note 86 — I. Preservation of Objects composed of Inorganic Substances.

Since chlorine compounds (especially common salt) form the predominating substance in the soluble salts contained in limestones their removal may be considered a proof that other salts (e.g. sulphates) have also been removed. Hence it is sufficient to prove the disappearance of chlorine. In the rare cases in which sulphates only are present, a test similar to that mentioned on p. 77, applied to clay objects, should be used. If the water used for soaking salt-containing limestone, earthenware, etc., gives no precipitate, or only turbidity with the silver solution, the determination of chlorine by titration is not applicable.