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other animal fluids, and convertible into red and blue indigo (urrhodin and uroglaucin). Chemically, it is indoxyl sulphate of potash, C8H6NSO4K, and is derived from the indol formed in the alimentary canal. Called also uroxanthin.

merism (Chem.), the condition or relation of certain (metameric) substances, which, while chemically identical (in that they have the same composition, the same molecular weights, and the same ultimate constitution), are yet physically different, as in their action on polarized light, as dextro- and lævo-tartaric acids…

tissues and organs, as the spleen, pancreas, etc., and likewise in the vegetable kingdom. Chemically it is to be considered as amido-caproic acid. (CH3)2CH.CH2.CH(NH2)-COOH. L-leucine, the natural form, is present in most proteins.

A whitish soluble powder used as a developer in photography. Chemically, it is the sulphate of methyl-p-amino-m-cresol.

time considered identical with choline, a crystalline body originally obtained from bile. Chemically, however, choline is oxyethyl-trimethyl-ammonium hydroxide, while neurine is vinyl-trimethyl-ammonium hydroxide. [Written also neurin.]

lement, tasteless and odorless, comprising four fifths of the atmosphere by volume. It is chemically very inert in the free state, and as such is incapable of supporting life (hence the name azote still used by French chemists); but it forms many important compounds, as ammonia, nitric acid, the cyanides, etc, and is a…

l and vegetable kingdoms (see Palmitin). It dissolves solid fats, especially at 30-40° C. Chemically, olein is a glyceride of oleic acid; and, as three molecules of the acid are united to one molecule of glyceryl to form the fat, it is technically known as triolein. It is also called elain.

e substance in which the mineral salts are deposited to form bone; -- called also ostein. Chemically it is the same as collagen.

he fat of animal tissues, with olein and butyrin in butter, with olein in olive oil, etc. Chemically, it is a glyceride of palmitic acid, three molecules of palmitic acid being united to one molecule of glyceryl, and hence it is technically called tripalmitin, or glyceryl tripalmitate.

translucent waxy substance, having a characteristic disagreeable smell. It is very active chemically, must be preserved under water, and unites with oxygen even at ordinary temperatures, giving a faint glow, -- whence its name. It always occurs compined, usually in phosphates, as in the mineral apatite, in bones, etc.…

o`to*graph"ic*al*ly, adv. Photographic printing, the process of obtaining pictures, as on chemically prepared paper, from photographic negatives, by exposure to light.

dioactive substance discovered by M. and MMe. Curie in pitchblende. It is closely related chemically to bismuth. It emits only alpha rays and is perhaps identical with radium F.

A copy of a print, writing, etc., made by placing it upon a chemically prepared paper which is acted upon by a gas which permeates the paper of the print, writing, etc.

ts compounds color flames carmine and give a characteristic spectrum. It resembles barium chemically. Radium preparations are remarkable for maintaining themselves at a higher temperature than their surroundings, and for their radiations, which are of three kinds: alpha rays, beta rays, and gamma rays (see these terms)…

either by acting machanically in preventing the color, etc., from reaching the cloth, or chemically in changing the color so as to render it incapable of fixing itself in the fibers.. The pastes prepared for this purpose are called resist pastes. F. C. Calvert.

tance, formed in the decomposition of creatin (one of the constituents of muscle tissue). Chemically, it is methyl glycocoll.

s a product of the putrefaction of albuminous matter. It is also found in reduced indigo. Chemically it is methyl indol, C9H9N.

To deprive of cohesion by combining chemically with water; to slake; as, to slack lime.

To color, as wood, glass, paper, cloth, or the like, by processess affecting, chemically or otherwise, the material itself; to tinge with a color or colors combining with, or penetrating, the substance; to dye; as, to stain wood with acids, colored washes, paint rubbed in, etc.; to stain glass.

lly increases the hardness, or raises the melting point, of the fat, as in mutton tallow. Chemically, it is a compound of glyceryl with three molecules of stearic acid, and hence is technically called tristearin, or glyceryl tristearate.