C A C 



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C A L 



C 



CACHO'LONG. A milk-white variety of 

 quartz, having a pearly, or glistening 

 lustre, a flat conchoidal fracture, and per- 

 fect opacity. It is found on the river 

 Cach, in Bucharia, and obtains its name 

 from that river and choloug, the Calmuc 

 word for stone. It is said by Brougniart 

 that the cacholong has been found in 

 calcareous breccia in France. 

 CA'DMIUM. A metal of a bluish-white 

 colour, with a specific gravity of 86. It 

 is the least malleable and ductile of all 

 metals which possess those properties. It 

 was discovered by Professor Stromeyer, 

 of Gottingen, in 1817, in some oxide, or 

 carbonate, of zinc ; it has subsequently 

 been found in the silicates of zinc of Der- 

 byshire, and in ores of that metal found 

 in other situations. The equivalent num- 

 ber of cadmium is 52-5. Cadmium has not 

 as yet been usefully employed in the arts. 

 CADU'COUS. (caducus, Lat.) In botany, 

 applied to leaves falling before the end of 

 summer ; to corollas falling off before the 

 dropping of the stamens ; to perianths 

 falling before the corolla is well un- 

 folded. 

 CAIRN. (Gael.) A name given to a heap 



of stones covering a dead body. 

 CA'LAITE. Mineral turquois. 

 CA'LAMAR. A name given to the cuttle-fish. 

 CA'LAMINE. (calamine, Fr. giallamina, 

 It.) Carbonate of zinc. Calamine is 

 found either loose, or in masses, or crys- 

 tallized ; colour white, grey, or yellow. 

 Before the blow-pipe it decrepitates, but 

 does not melt. It is used in the manu 

 facture of brass. It consists of oxide of 

 zinc 65, and carbonic acid 34. It con- 

 tains also some sesquioxide of iron. 

 CA'LAMITB. (from calamus, Lat. 

 Gr.) 



1. A genus of fossil equisetacese. Cala- 

 mites abound universally in the most 

 ancient coal formations, occur but spar- 

 ingly in the lower strata of the secondary 

 series, and are entirely wanting in the 

 tertiary formations, and also on the actua 

 surface of the earth. Brongniart enume- 

 rates twelve species of calamites. Cala- 

 mites are characterized by large and sim- 

 ple cylindrical stems, articulated at in 

 tervals, but either without sheaths, or 

 presenting them under forms unknown 

 among existing equiseta; they however 

 most differ from equiseta in their heigh 

 and bulk, sometimes exceeding seven 

 inches in diameter, whilst that of a living 

 equiseta rarely exceeds half an inch. A 

 calamite fourteen inches in diameter has 

 lately been placed in the museum at Leeds 



2. A mineral variety of hornblende, called 

 also Actynolite, or Actinolite. See Acti- 

 nolite. 



}ALC-SINTER. Stalactitical or stalagmiti- 

 cal carbonate of lime. This is so called 

 from the German kalk, lime, and sintern, 

 to drop. It is deposited from thermal 

 springs holding carbonate of lime in so- 

 lution. 



CALCAI'RE GRO'SSIER. (Fr.) A coarse 

 limestone, often passing into sand, and 

 abounding in marine shells. According 

 to Lyell, it belongs to the eocene tertiary 

 period, and is found in the Paris basin. 

 ALCAI'RE SILI'CIEUX. (Fr.) A compact 

 silicious limestone, occupying, according 

 to the early opinion of Brongniart, the 

 place of the calcaire grossier where that 

 is wanting, who discovered in it the sili- 

 cate of magnesia. Like the calcaire gros- 

 sier, the calcaire silicieux belongs to the 

 eocene tertiary period ; it has been found 

 in the Paris basin, in the Isle of Wight, 

 and in several parts of France. 

 CALCA'REOUS. ) (calcarms, Lat. calcaire, 

 CALCA'RIOUS. $ Fr. I do not remember 

 to have met with this word as here given, 

 spelt with an i, except in Webster, and I 

 believe, in this instance, his orthography 

 to be incorrect.) Partaking of the pro- 

 perties of lime ; containing lime in com- 

 position ; of a limy nature. 

 CALCA'REOUS ROCK. Limestone. 

 CALCA'REOUS SPAR. Crystallized carbon- 

 ate of lime. Calcareous spar occurs 

 crystallized in a vast variety of forms, but 

 its primitive form is invariably a rhom- 

 boid with obtuse angles of 105 5', and 

 74 55', the crystals break easily with the 

 stroke of a hammer. It consists of nearly 

 57 parts of lime and 43 parts and a frac- 

 tion of carbonic acid. The finest speci- 

 mens are brought from Derbyshire, but 

 it is found almost in all parts of the 

 globe. Calcareous spar is often as trans- 

 parent as rock-crystal, but it is usually 

 coloured of various tints by the presence 

 of oxide of iron. All its forms, which 

 amount to nearly 500, are derived from 

 the rhomb. When in irregular forms, it 

 may always be distinguished from quartz 

 by its admitting of being scratched with a 

 knife, and by its effervescing when weak 

 nitrous acid is applied to it. Iceland 

 spar is this mineral in its purest form, 

 and affords the readiest means of obser- 

 ving the optical phenomenon of double 

 refraction. Its almost universal diffusion 

 is probably owing to its partial solubility 

 in water; in this condition it filters 

 through the crevices abounding in all 



