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t gelatinous cones found in the compound eyes of certain insects, taking the place of the crystalline cones of others.

A kind of symmetry characteristic of certain crystals which from twinning, or other causes, come to resemble forms of a system other than that to which they belong, as the apparently hexagonal prisms of aragonite.

A pseudomorphous crystal, as a crystal consisting of quartz, but having the cubic form of fluor spar, the fluor crystal having been changed to quartz by a process of substitution.

The state of having, or the property of taking, a crystalline form unlike that which belongs to the species.

Not having the true form. Pseudomorphous crystal, one which has a form that does not result from its own powers of crystallization.

Vanadate of bismuth, occurring in minute reddish brown crystals.

ng to, or designating, an acid obtained by the decomposition of vulpinic acid, as a white crystalline substance.

A dyestuff resembling alizarin, found in madder root, and extracted as an orange or red crystalline substance.

A greenish yellow crystalline coloring matter found with pyocyanin in pus.

; dark red silver ore. It is a sulphide of antimony and silver, occurring in rhombohedral crystals or massive, and is of a dark red or black color with a metallic adamantine luster.

One of the less volatile hydrocarbons of coal tar, obtained as a white crystalline substance, C16H10.

A common mineral of a pale brass-yellow color and brilliant metallic luster, crystallizing in the isometric system; iron pyrites; iron disulphide. Hence sable coal his massy couch extends, And stars of gold the sparkling pyrite blends. E. Darwin.

A white crystalline substance, C6H4(OH)2, of the phenol series, found in various plants; -- so called because first obtained by distillation of gum catechu. Called also catechol, oxyphenol. etc.

A yellow crystalline substance allied to pyrrol, obtained by the distillation of gelatin.

meric with phloroglucin, obtained by the distillation of gallic acid as a poisonous white crystalline substance having acid properties, and hence called also pyrogallic acid. It is a strong reducer, and is used as a developer in photography and in the production of certain dyes.

Native lead phosphate with lead chloride, occurring in bright green and brown hexagonal crystals and also massive; -- so called because a fused globule crystallizes in cooling.

Having the property of crystallizing by the agency of fire.

Pertaining to, derived from, or designating, an acid obtained as a white crystalline substance by the distillation of mucic acid, or by the oxidation of furfurol.

Pertaining to, or designating, an acid, H4P2O7, which is obtained as a white crystalline substance. Its salts are obtained by heating the phosphates.

Pertaining to, or designating, an acid obtained as a white crystalline substance by the distillation of tartaric acid.