E M B 



[ 153 ] 



E M y 



1. In botany, the germ, or most 

 essential part of a seed, and with- 

 out which no seed is perfect, or 

 capable of re-production. The 

 embryo is usually placed within 

 the substance of the seed, either 

 central, excentral out of the centre, 

 or external ; its direction is curved 

 or straight, and in some instances 

 spiral. Flora Medica. 



2. The offspring yet enclosed in 

 the uterus, and in the early stage 

 only of uterogestation ; it is after- 

 wards called the foetus. 



EMBOUCHU'KE. (Er.) The mouth of 

 a river, or that part where it 

 enters the sea. 



E'MERALD. (emeraude, Er. smerdldo, 

 It. fjiapa^o's, Gr. smaragdus, Lat.) 

 A precious stone of a green colour, 

 found crystallized. Under the 

 genus emerald are comprised two 

 species, the first, the prismatic 

 emerald, or euclase of Werner and 

 Haiiy, and prismatischer smaragd 

 of Mohs ; the second, the rhombo- 

 hedral emerald, or rhomboedrischer 

 smaragd of Mohs. This last species 

 contains two varieties, the precious 

 emerald and the beryl, or common 

 emerald. Prof. Jameson places 

 the emerald amongst the members 

 of the schorl family, dividing it 

 into sub-species, namely, emerald 

 and beryl. He observes, " its 

 characteristic, and, we may almost 

 say, its only colour, is emerald 

 green, of all degrees of intensity 

 from deep to pale. The deep 

 sometimes inclines a little to verdi- 

 gris green, and oftener to grass- 

 green : the pale varieties sometimes 

 nearly pass into greenish- white." 

 Prof. Phillips says "the only im- 

 portant difference between emerald 

 and beryl is in their colours ; 

 which, since they present an 

 uninterrupted series, is altogether 

 insufficient for a division of the 

 species. The emerald and beryl 

 are crystallized compounds of an 

 earth called glucina, with silex, 



alumine, lime, and oxide of iron 

 the splendid green of the emerald 

 is attributed to the presence of 

 oxide of chromium. The finest 

 emeralds are brought from Peru. 

 Vauquelin, in analysing the eme- 

 rald, first discovered the earth 

 which he called glycina, or glucina. 

 Cleaveland says " the emerald is 

 always crystallized ;" Jameson 

 states, " it is said to occur masive, 

 and in rolled pieces," but of such 

 Werner has seen no specimens ; 

 Phillips says " it occurs in rolled 

 masses in secondary depositories." 

 The primitive form, of which Haiiy 

 has described six modifications, is 

 a regular hexahedral prism, whose 

 sides are squares. The integrant 

 particles are triangular prisms. 

 The emerald yields readily to 

 cleavage, parallel to all the planes 

 of its primary form. Before the 

 blow-pipe it fuses into a white, and 

 somewhat vesicular, glass. Speci- 

 fic gravity from 2'60 to 2'77. 

 Hardness from 7'5 to 8\ It 

 scratches glass easily, quartz with 

 difficulty. 



E'MEKY. (emeri, Fr. pierre ferrugi- 

 nemefort dure, dont on se sert pour 

 polir les m&taux et les pier res.) 

 The schmiergel of Werner; eme- 

 r'il of Brongniart ; corindon granu- 

 laire of Haiiy. A massive, nearly 

 opaque, greyish-black variety of 

 rhombohedral corundum, consist- 

 ing of alumina 86, silica 3, oxide 

 of iron 4. Emery sometimes occurs 

 in fine granular distinct concretions. 

 Lustre glistening ; fracture uneven, 

 and sometimes splintery. It is 

 sufficiently hard to scratch quartz. 

 Specific gravity from 3 '6 to 4. It 

 is found in Europe, Asia and 

 America. Emery powder is used 

 for the purpose of polishing metals 

 and hard stones, and also for 

 domestic purposes, sprinkled upon, 

 and fastened to, brown paper; 

 then called emery-paper. 



E'MYS. (from rj /LIVID, Gr.) Emydes, 



