LABORATORY. This term is generally applied to establishments for conducting chemical or physical investigations, or for chemical manufacture. Chemical laborato ries may be for purposes of instruction, as are those which are attached to colleges or other high schools. These institutions also sometimes have special laboratories for research. All large private manufacturing establishments where chemical processes are employed to a considerable extent have laboratories attached to them in which investiga lions are carried on; many of them in the nature of preparatory trials of processes, to facilitate the process of manufacture. A government manufactory is sometimes called a laboratory, and so are many smaller private establishments, as pharmaceutical labora tories, metallurgical laboratories, telegraph laboratories, etc. (The workshop of a taxi dermist is often, and properly, called a laboratory. It is interesting in studying the history of chemistry to observe the great change that has gradually taken place in the appliances and apparatus used in the laboratories, and also in some cases the similar ity of process. Much of the old apparatus was very complicated, a natural result of
the complex manner of thought from newly-formed theories or specula miops; it was apparatus made for the trial of things which seemed extremely occult. Heat, however, performed a very important part in the old alchemist's operations, as as in those of the modern chemist, and furnaces of various kinds have, therefore, always formed a part of laboratory furniture; but the modern forms of furnace or heat ing apparatus are much more efficient than the old, on account of the employment of elementary factors of combustion, whose more widely separated electrochemical prop erties cause more intense union, and therefore greater evolution of heat. The oxy hydrogen blowpipe was not used until Priestley's discovery of oxygen, the previously known hydrogen, phlogiston, or inflammable air, being until then a comparatively inert body.