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Electric

elements, light and weight

ELECTRIC electric light is now used in many large photographic works, and in a few studios for portraiture. For enlarging and printing it is now much used. The heavy outlay in an electric installation is, however, the chief drawback to its more universal use.

For portraiture at night the electric light is generally used, the light being fitted in the focus of a parabolic reflector, so that it will be reflected in parallel rays.

element is a substance that has hitherto resisted all efforts to divide it into simpler forms of matter, and it is therefore supposed to consist of one kind of matter only. The following is a list of the various elements at present known, with their symbol and atomic weight. Those marked with an asterisk are non-metallic elements, the remainder being metals, although the distinction is in reality not clearly defined, as one or two—arsenic and antimony, for instance— are on the border line.

Besides these there are one or two other doubtful elements, such as davyium, decepium, mosandeum, nephmium, etc., which cannot be entered in the above list, as their existence is doubted by many chemists, and the atomic weight unknown.

In the third column we have the atomic weight; hydrogen being the lightest element known, is taken as unity. See also Chemistry.

ELEML—The resinous product of various terebinthinous trees used for making varnishes. There are many varieties. The principal are obtained from the Balsamodendron ceylonicum of the West Indies, and the Icica :cicariba of the Brazils. A Mexican elemi is obtained from the Elaphrium elemiferum. It is a brown-yellowish translucent resin, having a peculiar odor resemb ling fennel. If added to varnishes it prevents their cracking as they dry. If distilled with water it yields a transparent colorless oil, which boils at 166°C.