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[64] 



CRY 



a jointed, hard, external covering, or 

 shell. 



CRU'STATED. (crustatus, Lat.) Covered 

 with a crust, or shell. 



CRUSTA'TION. A hard shelly covering ; 

 incrustation. 



CRY'OLITE. (from KpvoQ and X/0oc, Gr.) 

 Ice-stone. A rare mineral of a white, 

 brown, or red colour, hitherto found only 

 in Greenland, at the arm of the sea named 

 Arksut, where it occurs in gneiss, asso- 

 ciated with iron-pyrites and galena. It 

 consists of fluoric acid 44, soda 32, alu- 

 mina 24. 



CRYPTOGA'MIA. (from icpuTrroc, concealed, 

 and ydfioc, nuptials, Gr.) The 24th class 

 of plants in the Linnsean artificial system, 

 comprehending those whose fructifications 

 are concealed, either through minuteness, 

 or within the fruit. The carboniferous 

 era abounded in the vascular cryptogamia 

 to a degree unexampled at the present 

 time ; the plants belong to species and 

 genera now extinct, but allied to existing 

 types by common principles of organiza- 

 tion. The numerical preponderance of 

 the cryptogamia in the coal is such, that 

 while in the present order of nature, they 

 are to the whole number of known plants 

 as one to thirty, at that epoch they were 

 in the proportion of twenty-five to thirty. 

 In the saliferous system, about fifty spe- 

 cies have been ascertained, some of which 

 differ from any observed in the coal mea- 

 sures. The class Cryptogamia contains 

 the ferns, mosses, funguses, and sea- 

 weeds : in all of which the parts of the 

 flowers are either little known, or too 

 minute to be evident. 



CRYPTOGA'MIC. A term applied to plants 

 not bearing flowers with stamens and ova- 

 rium visible. Belonging to the class 

 Cryptogamia. Ferns, mosses, fungi, &c., 

 are cryptogamic plants. In the transition 

 rocks, about thirteen species of crypto- 

 gamic plants, four of which are algse, and 

 the remainder ferns, comprise all that is 

 known of the vegetable kingdom, anterior 

 to the carboniferous system. 



CRYPTOGA'MOUS. See Cryptogamic. The 

 family of ferns, both in the living and 

 fossil flora, is the most numerous of vas- 

 cular cryptogamous plants. 



CRY'STALS. (from /cpvoraXXoe, Gr. crys- 

 tallus, Lat. crystal, Fr. cristallo, It. 

 krystall, Germ.) There are many mineral, 

 or inorganic, substances, which assume 

 certain regular forms when becoming solid 

 from a fluid state, or when, after being 

 dissolved in a fluid, this fluid is evapo- 

 rated. These regular figures are termed 

 crystals. The cause of a body's possess- 

 ing this power, or property, is unknown, 

 but it is supposed to be connected with 

 the form of the molecules of which it is 



composed. Crystals are symmetrical 

 forms. There are six primitive forms of 

 crystals. 



1. The regular tetrahedron, having four 

 equilateral triangles for its faces. 



2. The regular cube of six squares for its 

 faces. 



3. A dodecahedron, or solid of twelve 

 faces, each being a rhombus. 



4. The octohedron, having eight triangles 

 for its faces. 



5. A six-sided prism. 



6. A parallelepiped, or a solid of six faces, 

 each two of which are parallel and equal, 

 as a cube, a rhomboid, &c. From these 

 six primitive forms of crystals, every va- 

 riety may be supposed to be produced by 

 cutting away its angles or edges in various 

 manners ; or by additions supposed to be 

 made on its faces. The regularity of the 

 figure will be influenced by the rapidity of 

 the evaporation, as when the evaporation 

 is hurried the crystals will be confused, 

 and wanting in regularity ; sometimes the 

 evaporation must be spontaneous, or not 

 assisted by the addition of heat, for pro- 

 curing regular and large crystals. It must 

 not be supposed that every mineral crys- 

 tallizes naturally in, or can be cut into, 

 all the forms, which might be deduced 

 from its primitive form ; but it never 

 occurs that the same mineral is found as- 

 suming a form, which cannot be shown on 

 these principles to be related to its primi- 

 tive, or in which primitive it either is 

 occasionally found, or to which the other 

 forms in which it occurs may not be re- 

 duced. Min. and Metals. 



When bodies dissolved in any fluid are 

 separated by crystallization, they are al- 

 ways found to retain a part of the fluid. 

 The water thus retained by saline crystals 

 is called the water of crystallization. This 

 water appears to be essential to the trans- 

 parent crystalline form of salts. Most 

 salts may be deprived of their water of 

 crystallization by heat ; some lose it in 

 the common temperature of the atmo- 

 sphere, and fall into a pulverulent mass ; 

 others attract moisture so strongly that 

 they, from exposure to the atmosphere, 

 deliquesce. 



CRY'STAL. Resembling crystal ; bright ; 

 clear ; transparent. 



CRY'STALLINE. (krystallen, Germ, crys- 

 tallin, Fr. cristallino, It.) Resembling 

 crystals ; bright ; clear ; transparent. 



CRY STALLINE HUMOUR. } (icpvardXivot;, 



CRY'STALLINE LENS. $ Gr. crystal- 



linus, Lat.) A solid body of a lenticular 

 form, being a part of the eye. It appears 

 most absurd ever to have given to this 

 solid body the name of humour. The 

 crystalline lens is situated behind the 

 aqueous humour, opposite to the pupil, 



