TEST

In Chemistry, any thing by which we distinguish the chemical nature of substances from each other: thus infusion of galls is a test of the presence of iron, which it renders evident by the production of a black colour in water and other liquids containing that metal; in the same way sulphuretted hydrogen is a test of the presence of lead, and nitrate of baryta of sulphuric acid. In Metallurgy and A aying, the porous crucible which absorbs the liquid vitrifiable oxide of lead and other metals combined with it is sometimes called the test. [s. 1238]