e A L 



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C A L 



strata, and recrystallizes as the water eva- 

 porates. When this nitration continues 

 so uninterruptedly as to prevent by its 

 mechanical action crystallization from 

 taking place, and yet so gradually as to 

 admit of the solid mineral being deposited 

 from the water, those curious and beau- 

 tiful concretions called stalactites are pro- 

 duced, which ornament, in so singular a 

 manner, most caverns in rocks or moun- 

 tains formed principally of limestone. 

 CALCA'REOUS TUFA. Beds of calcareous 

 tufa are sometimes formed in valleys, and 

 at the bottom of lakes, by a process which 

 bears some resemblance to chemical for- 

 mations. Springs containing carbonic 

 acid, that issue from limestone strata, 

 contain particles of carbonate of lime che- 

 mically dissolved in water ; but on ex- 

 posure to air and light, the carbonic acid, 

 which had but a slight affinity for the 

 particles of limestone, separates, and the 

 particles of lime are precipitated, and 

 form calcareous incrustations: these, in 

 the course of time, form beds, and occa- 

 sionally are of sufficient hardness to be 

 used for architectural purposes. Ther- 

 mal springs holding in solution calcareous 

 earth, rapidly deposit beds of calcare- 

 ous tufa. 



CALCEDO'NIC. Containing calcedony ; re- 

 sembling calcedony. 



CALCE'DONY. (calcedonius, Lat. calce- 

 doine, Fr. calcedonia, It. Sometimes 

 spelt chalcedony.) A semi-transparent 

 and translucent variety of quartz, to which 

 this name has been applied, from its hav- 

 ing been formerly found at Calcedon. It 

 is a simple, siliceous, uncrystallized mine- 

 ral. Flint nodules are frequently calce- 

 donic. When flints contain calcedony, 

 there may generally be perceived some 

 small bubbles, or a mammillated appear- 

 ance, in some part of the exterior of the 

 flint ; between calcedony and flint there 

 is a near resemblance, being only differ- 

 ent modes of the same substance. Spe- 

 cific gravity 2*56. There are several sub- 

 species ; the beautiful apple-green is 

 called chrysoprase ; the grass-green va 

 rieties, plasma ; those with red, brown 

 yellow, and green tints, carnelian ; others 

 are known as heliotrope, jasper, &c. these 

 will all be described under their severa 

 names, and in their proper order. 

 CALCI'FEROUS. (from calx and fero, Lat. 

 Producing lime ; containing lime ; yield 

 ing lime. 

 CA'LCINABLE. That is capable of behij 



calcined. 



CA'LCINATE. (calciner, Fr. calcinare, It. 

 To calcine ; to burn by fire to a calx, o 

 friable substance. 



CALCINA'TION. (calcination, Fr. calc 

 nazione, It.) The reduction by th 



action of fire of any substance to a con- 

 dition that it may be converted into a 

 state of powder. 



A'LCINE. (calciner, Fr. calcinare, It.) 

 To burn by fire to a calx, or friable sub- 

 stance. 



A'LCIUM. The metallic base of lime ; this 

 metal was obtained by Sir H. Davy from 

 lime by means of galvanic agency. Being 

 received during the process into a vessel 

 filled with naphtha, it was excluded from 

 oxygen, and consequently retained its 

 metallic appearance, which resembles that 

 of silver. But no further investigations 

 can be made in the present state of sci- 

 ence, regarding its properties as a metal, 

 for the instant atmospheric air is ad- 

 mitted to it, it absorbs oxygen rapidly, 

 burns with an intense white light, and re- 

 produces lime, which is an oxide of cal- 

 cium. 



^ALC-TUFF. A deposit of carbonate of 

 lime from calcareous springs. See Cal- 

 careous Tufa. 



}A'LIX. ) (/cvXt?, Gr. calix, Lat. ca/ice, 

 HA'LYX. \ Fr. calice, It. ) The calyx, or 

 flower-cup, is the outer expanded part, 

 or external covering of a flower, generally 

 resembling the leaves in colour and tex- 

 ture ; there are seven kinds of calyxes, 

 or calyces, namely, periantheum, amen- 

 tum, spatha, gluma, involucrum, volva, 

 pericha5tium. 



The calyx is the outer set of the floral 

 envelopes, when there are more than one 

 verticil of these. It is composed of two 

 at least, but generally more leaves, called 

 sepals. When the sepals are distinct, or 

 separate from each other, the calyx is 

 said to be polysepalous. In many plants 

 the sepals are joined together, more or 

 less, by their edges, so as to form one 

 piece in appearance ; in this case the 

 calyx is said to be monosepalous. When 

 all the sepals are alike in size and form, 

 the calyx is said to be regular. When 

 the sepals vary in size or form, the calyx 

 is said to be irregular. When the calyx 

 has one of its sepals hollowed out into a 

 long thin tube, as in the larkspur, gera- 

 nium, &c. it is said to be spurred. When 

 the calyx dies off soon after or immedi- 

 ately on its expanding, it is termed de- 

 ciduous ; this is commonly the case with 

 polysepalous calyces. When the calyx 

 survives the rest of the flower, either en- 

 closing or forming part of the fruit, it is 

 said to be persistent : most monosepalous 

 calyces are persistent. 

 CALP. A subspecies of carbonate of lime ; 



an argillo-ferruginous limestone. 

 CALY'MENE. (from KeKa\vmj.tvn, Gr. con- 

 cealed.) A genus of trilobites, which 

 appears to have been annihilated at the 

 termination of the carboniferous strata. 



