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SCAP'HOID. (from oicafai, a boat, and 

 et&>s, form, Gr.) The name given 

 to one of the carpal bones, from 

 its fancied resemblance to a boat, 

 or hollow oblong vessel. 



SCA'POLITE. Pyramidal felspar. The 

 scapolith of Werner ; scapolithe of 

 Brochant ; paranthine of Haiiy. A 

 rare mineral, occurring massive, 

 and in long prismatic crystals. It 

 consists of silica 43 '83, alumina 

 35-43, lime 18-96. It is of a grey, 

 yellowish, greenish- white, or silver 

 white colour. Specific gravity from 

 3-68 to 3-71. Before the blow- 

 pipe it intumesces, and fuses into 

 a shining, white enamel. It is 

 found in beds of magnetic ironstone 

 and iron pyrites, at Arendal, in 

 Norway. Jameson divides this 

 species into three subspecies, 

 namely, radiated scapolite, foliated 

 scapolite, and compact scapolite. 

 Its name is derived from the pris- 

 matic form of its crystals. 



SCA'PULA. The shoulder-blade. 



SCA'PTTLAB. Pertaining to the shoul- 

 der-blade or scapula. 



SCABF-SKIN. The cuticle or external 

 covering of the body ; called also 

 the epidermis. 



SCA'BBBOITE. An earthy mineral oc- 

 curring near Scarborough, whence 

 its name, of a pure white colour, 

 consisting of alumina, silica, perox- 

 ide of iron, and water. 



SCHAA'LSTEIN. Shell stone. The 

 schaal- stone of Jameson; pierre 

 calcaire testace*e of Brochant ; spath 

 en table of Haiiy. Called also 

 tabular spar or table spar. A 

 substance of a grey or pearly- white 

 colour, usually occurring in masses, 

 composed of thin laminee, collected 

 into large prismatic concretions. 

 It is very rare, and has been found 

 chiefly at Dognatska, in the Bannat. 



SCELIDOTHE'BIUM. (from <r/ce\*s, hind 

 leg, and Orfplov, beast, Gr.) A 

 genus or subgenus distinct from 

 Megatherium and Megalonyx, but 

 of the same natural family; dis- 



covered by Mr. Darwin in Patago- 

 nia, and so named by Prof. Owen. 

 The characters of this genus are 

 taken from the modifications of the 

 teeth and of the bones of the extre- 

 mities, especially of the astragalus. 



SCHEE'LIUM. Another name for Tung- 

 sten. 



SCHI'LLEE SPAB. (from scMlerm, 

 Germ.) The schiller spath of 

 Mohs. A genus of spars compri- 

 sing four varieties, namely, com- 

 mon schiller spar ; bronzite, or 

 hemiprismatic schiller spar; hy- 

 persthene, or prism atoidal schiller 

 spar; and anthophyllite, or pris- 

 matic schiller spar. The characters 

 of the genus are, the cleavage mo- 

 notomous, perfect. Metallic pearly 

 lustre. Hardness 3*5 to 6-0. Spe- 

 cific gravity 2-6 to 3*4. 



SCHIST. (<rx*0ro9, Gr.) A term sy- 

 nonymous with slate. A rock, of 

 a fissile character, which may 

 easily be split. 



SCHISTO'SE MI'CA. The name given 

 by Kirwan to mica slate, 



SCHKEIDE'BIAN MEMBBANE. Thus na- 

 med from Schneider, who first de- 

 scribed it. The lining membrane 

 of the nostrils. 



SCHOBL. (from Schorlan, a village 

 in Saxony.) Some mineralogists 

 comprise in one family, which they 

 term the Schorl family, topaz 

 schorlite, pyrophysalite, euclase, 

 emerald, iolite, schorl, epidote, 

 zoisite, and axinite. Others con- 

 sider tourmaline and schorl as one 

 mineral. Under the word schorl 

 we shall describe, not the family, 

 but the mineral known as the Schorl 

 of Werner, Le Schorl of Brochant, 

 the Tourmaline of Haiiy. Jameson 

 divides schorl into Precious Schorl 

 and Common Schorl. It is a 

 mineral, in general, easily recog- 

 nised. It most frequently occurs 

 in long prismatic crystals, more or 

 less regular, whose lateral faces 



