A V E 



A X 1 



Automalite is placed by some 

 mineralogists in the ruby family; 

 by others it is considered to be a 

 variety of spinel, and from the 

 large quantity of oxide of zinc 

 which enters into its composition it 

 has been termed zinciferous spinel. 

 Externally it is glistening ; lustre 

 pearly, inclining to semi-metallic. 

 Internally it is shining on the 

 principal fracture, but glistening 

 on the cross fracture, and the lustre 

 resinous. Fracture foliated, ex- 

 hibiting a four- fold cleavage parallel 

 with the planes of the octahedron. 

 It is heavier than spinel, its specific 

 gravity being 4'1 to 4'3, from which 

 it also differs in being nearly opaque, 

 and of a dark bluish-green colour 

 by transmitted light. It is of 

 sufficient hardness to scratch quartz. 

 It is brittle and easily frangible. 

 Before the blow-pipe it is infusible. 

 It is a non-conductor of electricity. 

 Its constituent parts are alumina, 

 ths oxides of zinc and iron, silica, 

 and sometimes magnesia. It has 

 been found in America and in 

 Sweden. 



AUTO'MOLITE. See Automalite. 



A'VALANCHE. (avdlange, ou avalanche, 

 Fr.) A mass of snow which, 

 detached from any mountainous 

 height, by rolling onwards accu- 

 mulates frequently prodigious bulk 

 and acquires great momentum. 

 Avalanches are in mountainous 

 countries productive of the direst 

 misfortunes, sweeping before them 

 in their irresistible and destructive 

 progress every impeding object; 

 breaking off large masses of rocks, 

 uprooting, or tearing away, the 

 noblest trees, damming up river 

 courses, and burying beneath their 

 volumes villages, with their whole 

 population. 



A v' AN TURIN E. | Quartz Hyalin Aven- 



AY'ENTTJRINE. j turine of Haiiy. A 

 variety or sub-species of quartz, 

 exhibiting numerous points or spots 

 that glitter like gold. This appear- 



ance is generally owing to the 

 intermixture of small laminae of 

 mica; in some instances it is caused 

 by reflexion from numerous small 

 rents or fissures, in the stone. The 

 name is said to be derived from the 

 French, par avanture ; a workman 

 having first found it by accident. 



AVELL'ANA. A genus of shells for- 

 merly attributed to Auricula, oc- 

 curring in the Lower Chalk of 

 Lyme Regis, the Gault of Folkstone, 

 and in the Greensand. 



A'VES. The second of the sub-king- 

 dom vertebrata, comprising eight 

 orders of birds. 



AVER'TEBRATE. Having no vertebrae; 

 destitute of vertebrae. 



AVI'CULA. (from avis, Lat.) A genus 

 of inequivalved, fragile, rather 

 smooth bivalves; the base trans- 

 verse and straight, with produced 

 extremities and caudiform an- 

 teriorly; the left valve notched; 

 the hinge linear; with a tooth in 

 each valve beneath the beaks ; the 

 ligamental area marginal, narrow 

 and grooved, not traversed by the 

 byssus. Parkinson. Many species 

 of auricula have been recorded from 

 the Neocomian rocks of France, but 

 the genus is doubtful. Lycett. 



AXE-STONE. A mineral found in New 

 Zealand and the islands of the 

 Pacific, and by the inhabitants 

 made into axes and other cutting 

 instruments, from which circum- 

 stance it has obtained its name. 

 It is a sub-species of jade, and in 

 many respects resembles nephrite, 

 or nephritic stone. See Jade. 



AXI'LLA. (axilla, Lat.) 



1. In anatomy, the arm-pit. 



2. In botany, the angle formed by- 

 the stalk of a leaf with the stem. 



AXI'LLARY. (axillaris, Lat. axillaire, 

 Fr.) 



1. In botany, applied to peduncles 

 when proceeding from the angle 

 made by the leaf and stem, or 

 branch and stem ; also to flowers, 



