Search the Dictionary

veral plants of the cress kind found on rocks, as Arabis petræa, A. lyrata, etc. -- Rock crystal (Min.), limpid quartz. See Quartz, and under Crystal. -- Rock dove (Zoöl.), the rock pigeon; -- called also rock doo. -- Rock drill, an implement for drilling holes in rock; esp., a machine impelled by steam or compresse…

base, C20H21N3O, obtained by oxidizing a mixture of aniline and toluidine, as a colorless crystalline substance which forms red salts. These salts are essential components of many of the socalled aniline dyes, as fuchsine, aniline red, etc. By extension, any one of the series of substances derived from, or related to,…

A hydrous arsenite of cobalt, occuring in small red crystals, allied to erythrite.

Pertaining to, or designating, an acid extracted from madder root. It is a yellow crystalline substance from which alizarin is obtained.

ometimes verging to violet, or intermediate between carmine and hyacinth red. It is a red crystallized variety of corundum.

rtaining to, or designating, an acid which is obtained from gallic acid as a brown or red crystalline substance, and is related to rufiopin and anthracene.

A yellowish red crystalline substance related to anthracene, and obtained from opianic acid.

A phenol derivative of anthracene obtained as a white crystalline substance, which on oxidation produces a red dyestuff related to anthraquinone.

A yellow crystalline substance found in the root of yellow dock (Rumex crispus) and identical with chrysophanic acid.

a reddish brown color, and brilliant metallic adamantine luster, occurring in tetragonal crystals. In composition it is titanium dioxide, like octahedrite and brooklite.

the leaves of the rue (Ruta graveolens) and other plants, and obtained as a bitter yellow crystalline substance which yields quercitin on decomposition.

A bitter white crystalline substance obtained from the saccharinates and regarded as the lactone of saccharinic acid; -- so called because formerly supposed to be isomeric with cane sugar (saccharose).

A white crystalline substance, C6H8O6, obtained by the oxidation of saccharin, and regarded as the lactone of saccharonic acid.

Resembling sagenite; -- applied to quartz when containing acicular crystals of other minerals, most commonly rutile, also tourmaline, actinolite, and the like.

h. (Old Chem.) See Alembroth. -- Sal ammoniac (Chem.), ammonium chloride, NH4Cl, a white crystalline volatile substance having a sharp salty taste, obtained from gas works, from nitrogenous matter, etc. It is largely employed as a source of ammonia, as a reagent, and as an expectorant in bronchitis. So called because…

Aërated salt; a white crystalline substance having an alkaline taste and reaction, consisting of sodium bicarbonate (see under Sodium.) It is lagerly used in cooking, with sour milk (lactic acid) or cream of tartar as a substitute for yeast. It is also an ingridient of most baking powders, and is used in the preparatio…

e leaves of several species of willow (Salix) and poplar, and extracted as a bitter white crystalline substance.salicyl alcohol glucoside, salicyl alcohol b-D- glucopyranoside, saligenin b-D-glucopyranoside, C13H18O7. It is used in biochemistry as a standard substrate for evaluating the potency of b-glucosidase in enzy…

(carbolic acid) by the action of carbon dioxide on heated sodium phenolate. It is a white crystalline substance. It is used as an antiseptic, and in its salts in the treatment of rheumatism. Called also hydroxybenzoic acid.

A white crystalline substance obtained by dehydration of salicylic acid.

A phenol alcohol obtained, by the decomposition of salicin, as a white crystalline substance; -- called also hydroxy-benzyl alcohol.