or ELABORATORY, the chemists' work-house, or the place where they perform their operations, where the furnaces are built, their vessels kept, &c., and in general the term laboratory is applied to any place where physical experiments in pharmacy, chemistry, pyrotechny, &c., are performed.

As laboratories must be of very different kinds, according to the nature of the operations to be performed in them, it is impossible that any directions can be given which will answer for every one. Where the purposes are merely experimental, a single furnace or two of the portable kind will be sufficient. It is scarce needful to add, that shelves are necessary for holding vessels with the products of the different operations; and that it is absolutely necessary to avoid confusion and disorder, as by these means the products of the operations might be lost or mistaken for one another. Mortars, filters, levigating stones, &c., must also be procured: but from a knowledge of the methods of performing the different chemical operations will easily be derived the knowledge of a proper place to perform them. them in; for which see the articles Chemistry, Metallurgy, and Furnace.

military affairs, signifies that place where all sorts of fire-works are prepared, both for actual service and for pleasure, viz. quick-matches, fuzes, port-fires, grape-shot, case-shot, carcases, hand-grenades, cartridges, shells filled, and fuzes fixed, wads, &c. &c.