crystallogeny

[Gr. krystallos =crystal; gennao to produce.] That branch of science which treats of the formation of crystals. crys-tal-log-raph-er, 8. [Eng. crystallo graph (y); -er.] One who describes or investigates and the manner of their formatio IMG:content-1484.png:[ocr errors][merged small][merged small] Forbes: Literary Papers, 165. crys-tal-lô-grăph-ic, crystal-lô-graph-ical, a. [Eng. crystallograph (y); -ic; -ical.] Of or pertaining to crystallography. "The following are convenient, simple rules for use in connection with crystallographic measurements and calculations."-Dana: Mineralogy (5th ed.), p. xxviii. crys-tal-lô-graphic-al-ly, adv. [Eng. crys tallographical; -ly.] 1. After the manner of a crystallographer, or of IMG:content-1485.png:[blocks in formation] crystalloid particles of matter composing the crystal may be supposed to arrange themselves. Such imaginary lines are called the axes of the crystal. If skillfully chosen they become somewhat more than imaginary lines, for they may coincide with the optical axes of the crystal if it po e double refraction. Áccording to the number, relative length, position, and inclination to each other of these lines depends the outward form of the crystal. Dana enumerates the following "systems of crystallization:" (1) Having the axes equal-the Isometric system. (2) Having only the lateral axes equal=the Tetrag onal and Hexagonal systems. (3) Having the axes unequal=the Orthorhombic, Monoclinic, and Triclinic systems. (See these words.) "Instruction in crystallography is also attainable." Phillips: Mineralogy (2d ed.), Pref.