ferrous

It gave a bluish-black color with impure ferrous sulphate and a dark color with ferric chloride.

Exceedingly sensitive tests are known for the ferrous and the ferric ions.

Perhaps the most instructive case of this kind, that we can study, is that of iron in ferrous and ferric salts.

If the zinc sulphide were not the less soluble, it would be rapidly converted into the black ferrous sulphide.

It is a comparatively easy matter to determine the relative solubility of zinc and ferrous sulphides.