C H O 



223 



C II O 



slender; supposed to arise from the want 

 of sufficient light. 



CHLOROXAL'IC ACID, a compound ob- 

 tained by exposing acetic acid and^chlorine 

 to bright sunshine. It may be regarded 

 as a compound of 1 of hydrochloric acid, 

 and 1 of oxalic acid. 



CHLOR0RETS, compounds of chlorine. 



CHO'ANITE, a zoophyte of the chalk- 

 formation, called the petrified sea-ane- 

 mone by lapidaries : it bears a close 

 resemblance to the recent Alcyonia. 

 Named from %oxvr,, a funnel, in allusion 

 to its shape, which is sub-cylindrical, 

 with root-like processes, and having a 

 cavity or sac. which is deep and small in 

 comparison to the bulk of the animal. 



CHOCK, in marine language, a kind of 

 wedge, for confining a cask or other body 

 to prevent it from moving. The chocks of 

 the rudder are pieces of timber kept in 

 readiness to stop the motion of the rudder 

 in case of an accident, &c. In the con- 

 struction of framing a chock is an angular, 

 commonly a triangular shaped piece, 

 checked into the ends of the two pieces, 

 to be joined and fastened by treenails to 

 the ends forming the joint. See COAK. 



CHOC'OLATE, an article of diet prepared 

 from the cacao-nut, and thus named, ac- 

 cording to Dr. Alston, from two Indian 

 words, choco, sound, and atte. water, be- 

 cause of the noise made in its preparation. 

 To prepare it, the nuts are first roasted 

 like coffee ; and being next reduced to 

 powder, and mixed with water, the paste 

 is put into moulds of the desired shape. 

 It speedily hardens, and is then taken 

 out, wrapped in paper, and sent to mar- 

 ket. This alimentary preparation was 

 first used in Mexico, from which country 

 the Spaniards introduced it into Europe 

 in the year 1520. It was by them long 

 kept a secret from the rest of the world. 

 The proper flavouring admixture is va- 

 nilla, but cinnamon and cloves are more 

 commonly used because of their compa- 

 rative cheapness. See CACAO. 



CHOIR {^fj^a;}. In architecture, the part 

 of a church in which the choristers sing 

 divine service. 



CHOKE'-DAMP, a name given by miners 

 to all irrespirable gases, especially car- 

 bonic acid gas. 



CHOLE'DOCH us (^;X), and ^i^ofMti, I 

 receive) : one of the ducts of the liver is 

 called the ductus communis choledochus. 



CHOI/ERA, a word derived, according to 

 Ctjlsus, from 8>.)7, bile, and ^nu, to flow, 

 thus signifying a flow of bile ; according 

 to Alexander of Tralles, it is derived 

 from /.;, the intestine, and eiu, to flow, 

 signifying intestinal fluid; others again 

 derive it simply from %oA;i bile. The 

 name cholera is now applied to two dis- 

 eases utterly dissimilar, viz.. to a com- 



mon bilious disease long known in this 

 and most other countries, and to a malig- 

 nant disease of recent origin which com- 

 menced in Hindustan, and has since 

 diffused itself epidemically in various 

 directions. The first is usually called 

 common, and here British cholera, and the 

 second is malignant, Asiatic, blue, and 

 pestilential cholera, or cholera morbus. 



CHOLESTER'IC ACID. AVhen cholestorine 

 is treated with nitric acid, a peculiar acid 

 is formed called the eholestrri,;. It is ir. 

 crystals of a yellowish white colour, little 

 soluble in water, but abundantly so in 

 boiling alcohol. 



CHOLES'TERINE, a pearly substance found 

 abundantly in human biliary calculi, 

 whence its name, from Ai, bile,) and 

 ffrtfrof, solid. 



CUOUAM'BIC, a verse having an iambic 

 foot in the fifth place, and a spondee in 

 the sixth or last. The word is 

 (claudus}, and iat/ibic (q.v.). 



CHONDRIL'LA, the gum-succory. A ge- 

 gus of perennial plants. St/mjenesia 

 1'uly. tequalis. Name from ov 5g*v a grain 

 of corn, and so called because it emits 

 small particles of gum- like grains. 



CHONDROL'OGY, a description of the car- 

 tilages of the human body. %ov%%os and 



CHON'DRO-PHAR\NG.E'CS, a muscle so 

 named from %otfyo; and <ptiy|, because 

 it rises in the cartilaginous part of the 

 tongue, and is inserted in the pharynx. 



CHOSDRO-PTER-Y'GII, a class of fishes di- 

 vided into two orders, Chondropterygii 

 branchiis liberis, and Chondropterygii 

 branchiis fixis. The skeleton of these 

 fishes is essentially cartilaginous ; hence 

 the name from 93gaj, cartilage, and 

 s-TEfov, a fin, that is cartilaginous-jinned. 

 The sturgeon and shark are examples of 

 this class, and of the orders composing it . 



CHORAGIC MONUMENT, %0?- In Gre- 

 cian architecture, a monument erected in 

 honour of the Choragus who gained tho 

 prize by the exhibition of the best musi 

 cal or theatrical entertainment at the 

 festivals of Bacchus. 



CHORD, Lat. chorda, an intestine of 

 which strings were made. In music, 1. 

 The string of a musical instrument. - 

 2. The union of two or more sounds, 

 forming an entire harmony; as a third. 

 fifth, and eighth, which are perfect chords. 

 The fourth and sixth are imperfect chords. 

 In geometry, the right line which joins 

 the two ends of an arc. 



CHORE'A, St. "Vitus's dance, %? , a 

 dance. A disease which chiefly attacks 

 young people of \veakly constitution, and 

 which manifests itself in convulsive mo- 

 tions of the limbs, occasioning strange 

 and invc lun tary gesticulation*. 



