C H L 



[46] 



C H R 



being cased in a coat of armour. The 

 chlamyphorus and armadillo are th 

 only known animals that have a compact 

 coat of plated armour. The chlamy- 

 phorus lives almost entirely in burrows 

 beneath the surface of sandy plains ; its 

 scales are of a dense substance, resem- 

 bling hard leather. 



CHLO'RITE. (from Y,Xo>p6g, Gr.) A mi- 

 neral, consisting of silica 27-43, alumina 

 17'9, lime 0'50, oxide of iron 30'63, 

 magnesia 14'56, potash 1'56, water 

 6'92. It is a dark green variety of talc ; 

 has a glistening lustre ; minutely foliated 

 structure ; is soft and unctuous to the 

 feel ; and has obtained its name from its 

 colour. There are several varieties of 

 talc having a dark green colour, and 

 these are known as compact chlorite, 

 earthy chlorite, chlorite slate, foliated 

 chlorite, &c. Chlorite and talc pass by 

 insensible gradations into each other, 

 and in this state they supply the place of 

 mica, in most of the granitic rocks in the 

 vicinity of Mont Blanc. 

 CHLO'RITE-SCHIST. A metamorphic rock, 

 of a green slaty character, abounding with 

 chlorite. 

 CHLORI'TIC-SAND. Sand, coloured green 



by an admixture of chlorite. Lyell. 

 CHLORI'TIC. Resembling chlorite ; con- 

 taining chlorite. 



CHLORI'TIC GRANITE. Granite contain- 

 ing particles of chlorite. 

 CHO'ANITE. A zoophyte of the chalk for- 

 mation, intermediate between Alcyonia 

 and Ventriculites. Dr. Mantell, in his 

 " Wonders of Geology," states, " the 

 choanite, called petrified sea-anemone 

 by lapidaries, bears a close resemblance 

 to the recent Alcyonia. In the choanite, 

 crucial spines, resembling those in the 

 recent Alcyonia, may be detected. The 

 choanite is of a sub-cylindrical form, 

 with root-like processes, and having a 

 cavity or sac, which is deep and small 

 in comparison to the bulk of the animal. 

 The inner surface is studded with pores, 

 which are the terminal openings of tubes, 

 disposed in a radiating manner, and 

 ramifying through the mass." The beau- 

 tiful pebbles found on the shores of Bog- 

 nor and Worthing owe their markings to 

 the internal structure of the choanite, 

 and these are worked into a variety of 

 ornaments, as brooches, buckles, ear- 

 rings, &c. &c. Some lately found at 

 Worthing have been sold, when cut and 

 polished, at high prices. One of the 

 finest collections has been made by 

 Captain Tompkins, of that town. 

 CHOAN'ITES KONIGI. A species of choa- 

 nite to which this name has been given, 

 by Dr. Mantell, " in honour to Charles 

 Konig of the British Museum." This 



fossil is figured in Dr. Mantell's Geology 

 of the south-east of England, who therein 

 states that it is inversely conical ; exter- 

 nally marked with irregular fibres, some 

 of which penetrate the substance, and 

 terminate in openings on the inner sur- 

 face ; central cavity, cylindrical, deep, 

 narrow ; base fixed by radical processes. 

 This species is for the most part en- 

 veloped in large irregular flints, which 

 exhibit but slight traces externally of the 

 body they enclose. Dr. Mantell. 



CHOKE-DAMP. A name given by miners 

 to carbonic acid. 



CHO'NDRODITE. Hemiprismatic chrysolite. 

 Another name for brucite ; a mineral 

 composed of magnesia 54, silica 32, 

 fluoric acid 4, oxide of iron 2, potass 1, 

 and water 1. 



CHROME. > (from %pw^ta, colour, Gr.) 



CHRO'MIUM. $ This mineral is said to 

 have obtained its name from the property 

 it possesses of imparting colour to other 

 bodies in a very remarkable degree. 

 Chromium was first discovered by Vau- 

 quelin in 1797, after a variety of discor- 

 dant analyses made by Macquart, Bind- 

 heim and others. Its principal ore is 

 found in Siberia, and is a salt of lead, 

 formed by an acid oxide of chromium. 

 To the presence of chrome the emerald 

 and the ruby owe their hues. It is used 

 in tinting glass of an emerald green. 



CHRY'SALIS. (from xpvtroc, gold, because 

 of the golden colour in the nymphae of 

 some insects.) A state of rest and seem- 

 ing insensibility, which butterflies, moths, 

 and several other kinds of insects, pass 

 through before they arrive at their winged 

 or most perfect state. It is also called 

 aurelia. The figure of the aurelia or 

 chrysalis generally approaches to that of 

 a cone, and in this state it appears to 

 have neither legs nor wings, nor any 



Swer of locomotion ; it seems indeed to 

 ve hardly so much as life. The time 

 the duration of the animal in its chry- 

 salis state is different in different species, 

 for while some remain a few days only, 

 others continue eight months. 



CHRYSOBE'RYL. (from xpv^oc, gold, and 

 (3rjpv\\iov, gemma.) The cymophane 

 of Haiiy. Chrysopal of Delametherie. 

 Werner first made the chrysoberyl a dis- 

 tinct species, and gave it the name which 

 it now bears. Colour, a light yellowish 

 or asparagus green. This gem is found 

 in the Brazils, in Ceylon, in America, and 

 in Siberia. It consists of alumina 76'75, 

 glucina 17'79, and protoxide of iron 4-50. 



CHRY'SOLITE. (from xpvtroc, gold, and 

 \i9oQ, a stone, chrysolite, Fr.) The 

 Peridot of Haiiy, and Krisolith and Olivin 

 of Werner. The term chrysolite was 

 applied, without any regard to distinction, 



