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An optical property of some crystals which exhibit a star- shaped by reflected light, as star sapphire, or by transmitted light, as some mica.

An oxychloride of copper, usually in emerald-green prismatic crystals.

A poisonous, white, crystallizable alkaloid, extracted from the Atropa belladonna, or deadly nightshade, and the Datura Stramonium, or thorn apple. It is remarkable for its power in dilating the pupil of the eye. Called also daturine.

A hydrous carbonate of copper and zinc, found in pale green or blue crystalline aggregations. It yields a kind of brass on reduction.

A lemon-yellow phosphate of uranium and calcium occurring in tabular crystals with basal cleavage, and in micalike scales. H., 2- 2.5. Sp. gr., 3.05-3.19.

A crystalline globulin, contained in oat kernels, very similar in composition to excelsin, but different in reactions and crystalline form.

variety of oligoclase with internal firelike reflections due to the presence of minute crystals, probably of hematite; sunstone.

eet; to shun; to abstain from; as, to avoid the company of gamesters. What need a man forestall his date of grief. And run to meet what he would most avoid Milton. He carefully avoided every act which could goad them into open hostility. Macaulay.

A borosilicate of alumina, iron, and lime, commonly found in glassy, brown crystals with acute edges.

f several imaginary lines, assumed in describing the position of the planes by which a crystal is bounded.

A substance (C6H5.N2.C6H5) derived from nitrobenzene, forming orange red crystals which are easily fusible.

A mineral occurring in triclinic crystals approaching pyroxene in angle, and of a greenish black color. It is a silicate of iron, manganese, and lime.

A division for the stalls of an open stable.

A white, crystalline substance,

ive sulphate of barium, a mineral occurring in transparent, colorless, white to yellow crystals (generally tabular), also in granular form, and in compact massive forms resembling marble. It has a high specific gravity, and hence is often called heavy spar. It is a common mineral in metallic veins.

timber, ships, etc., esp. (a) the sessile species (genus Balanus and allies), and (b) the stalked or goose barnacles (genus Lepas and allies). See Cirripedia, and Goose barnacle. Barnacle eater (Zoöl.), the orange filefish. -- Barnacle scale (Zoöl.), a bark louse (Ceroplastes cirripediformis) of the orange and quince…

A mineral of a white or gray color, occurring massive or crystallized. It is a compound of the carbonates of barium and calcium.

elating to, or forming, the base. Basal cleavage. See under Cleavage. -- Basal plane (Crystallog.), one parallel to the lateral or horizontal axis.

The basal plane of a crystal.

Said of crystalline rocks which contain a relatively low percentage of silica, as basalt. Basic salt (Chem.), a salt formed from a base or hydroxide by the partial replacement of its hydrogen by a negative or acid element or radical.