CO H 



COL 



remarkable for the production of cochi- 

 neal and other valuable dyes. 



CO'CCOLITE {k6kko9, a kernel, Xt'^of, 

 a stone). A green mineral, occurring in 

 loosely aggregated concretions, together 

 with granular limestone and other sub- 

 stances, in beds subordinate to the trap 

 formation. 



COCCOO'N {kokkov, a berry or kernel). 

 The silken case which certain insects 

 spin for a covering during the period of 

 their metamorphosis, as that of the silk- 

 worm when passing into the pupa state. 



CO'CCUS (^k6kko<:, a kernel). A term 

 applied, in Botany, to a pericarp of dry, 

 elastic pieces, or coccules, as in Euphor- 

 bia. In this plant, the cocci are three in 

 number, and the fruit, generally called a 

 regma, is therefore also termed a tricoc- 

 cous capsule. 



COCHINE'AL. The technical name of 

 the coccus cacti, a homopterous insect, 

 brought from Mexico, and employed by 

 dyers. Cochinilin is a colouring matter 

 obtained from cochineal, and is a consti- 

 tuent of carmine. The term granilla is 

 applied to very small insects of this kind, 

 from their resemblance to little grains. 



CO'CHLEATE (cochlea, from KoxXof, 

 a conch). Shell-shaped; shortly spiral, 

 like a snail's shell, as the legume of 

 medicago falcata. 



COCI'NIC ACID. Cocostearic acid. 

 The crystallizable acid of the butter of 

 the cocoa nut. 



CO'DA {coda, Ital., a tail). In Music, 

 a passage of variable length at the end 

 of a movement which follows a length- 

 ened perfect cadence. 



CO'DEINE {K<o&€ia, a poppy head). 

 One of the vegetable bases of opium. 



CO-EFFICIENT. A term applied, in 

 Algebra, to the number, negative or 

 positive, which is prefixed to any alge- 

 braical quantity, to show how often it is 

 to be taken. It is that factor which is a 

 number, as 3a, or 5a'^c. 



CGELELMI'NTHA {ko'iXo^, hollow, 

 t'\/utv9, a worm). Intestinal worms which 

 are hollow, and contain an alimentary 

 tube in the cavity of the body. These 

 are the cavitary intestinal worms of Cu- 

 vier, the nematoidea of Rudolphi. 



CCENO'BIO (KOii/6/3to9, living in com- 

 munion with others). The term by 

 which Mirbel designates the fruit of the 

 Labiatae. It differs from the carcerule 

 merely in the low insertion of the style 

 into the ovaria, and the distinctness of 

 the latter. 



COHE'SION {cohcereo, to stick to- 



gether). That relation among the com- 

 ponent parts of a body, by which they 

 cohere, or are kept together. The un- 

 known principle by which particles co- 

 here is called the attraction of cohesion. 

 On the degree of this force depend the 

 aggregate forms of matter, distinguished 

 as the solid, the liquid, and the gaseous. 



COHOBA'TION. The continuous re- 

 distillation of a liquid from the same 

 materials, or from a fresh parcel of the 

 same materials. 



COKE. The residue of coal, when the O A 



volatile matters have been driven off. 



CO'LCOTHAR. The brown-red oxide 

 of iron, which remains after the distilla- ^ / 



tion of the acid from sulphate of iron. 



It is used for polishing glass, &c., under . 



the name of crocus, or crocus martis. ^ ' / /2 



COLEOPHY'LLUM [KoXeo^, a sheath, 

 <pv\\ov, a leaf). Coleoptile. In Botany, 

 the sheath within which the young leaves 

 of monocotyledons are developed. By 

 the term coleorrhiza (pi^a, root), Mirbel 

 designates the sheath at the base of the 

 radicle of monocotyledons. 



COLEOTTERA (Ko\e6?, a sheath, 

 TTTepov, a wing). Sheath-winged insects ; 

 an order of insects which have four 

 wings, the upper pair being crustaceous, 

 and forming a sheath, or shield {elytron), 

 to the lower pair, as in the beetle. The 

 order has been distinguished by Latreille, 

 with reference to the number of joints 

 in the tarsi, or divisions of the foot, into 

 the pentamera, heteromera, tetramera, 

 and trimera. 



COLLE'CTOR, ELECTRICAL. The 

 upper plate or disc of a condenser, em- 

 ployed for collecting electricity. 



COLLE'CTORS. A term applied, in 

 Botany, to those hairs with which the 

 style of Compositae, Campanulaceae, and 

 others, is often densely covered, and 

 which seem intended as brushes to col- 

 lect and clear the pollen out of the cells 

 of the anthers. 



COLLE'NCHYMA {KoWa, glue, 4V 

 XvjJia, infusion). A term applied by 

 Link to the cellular substance in which 

 the pollen of Orchidaceous and Ascle- 

 piadaceous plants is generated. It is 

 supposed to constitute the appendage of 

 the pollen-masses of the former of these 

 tribes of plants. 



COLLIMA'TION, LINE OF {collimo, 

 for collineo, to level, or aim in a right 

 line). The line of sight in an astronomi- 

 cal or geodesical instrument. The central 

 line of a telescope, or that which joins 

 the centres of its object-glass and its eye- 

 E6 



