II Y M 



[ 122 ] 



JAN 



bees in building their cells ; the wasps in 

 scraping particles of wood from posts and 

 rails for a similar purpose, and likewise 

 to seize their prey ; but the great instru- 

 ment by which they collect their food is 

 their tongue; this the bees particularly 

 have the power of inflating, and can wipe 

 with it both convex and concave surfaces ; 

 and with it they lick, but not suck, the 

 honey from the blossoms, for Reaumur 

 lias proved that this organ acts as a 

 tongue and not as a pump. Some of 

 the Hymenoptera prefer a vegetable 

 diet. 



HYMENO'PTEROUS. Belonging to the order 

 Hymenoptera ; having tour membranous 

 wings 



HY'PERSTHENE. ) (from v-n-ep and 



HY'PERSTENE. j Gr. ) Prismatoidal 

 Schiller-spar. Labrador Schiller-spar. A 

 mineral of a greenish-black colour, but 

 on the cleavage of a copper-red. Occurs 

 in granular and lamellar concretions, 

 and massive. It is found in Labrador, 

 in the Isle of Skye, in Banffshire, and in 

 the Shetland Isles. It is composed of 

 silica, magnesia, alumina, lime, and oxide 

 of iron, the last of which is said to form 

 one-fourth of the whole. 



HYPERSTHE'NIC. Containing hypersthene ; 

 resembling hypersthene. 



HYPOCRATE'RIFORM. Salver-shaped : a 

 term applied to a monopetalous corolla, 



the limb of which being placed on a tube, 

 spreads out horizontally. 



HYPOGA'STRIC. (from VTTO and yctoTJ/jO, 



. Gr.) Belonging to that region of the 

 abdomen which is called the hypogas- 

 trium. 



HYPOGA/STRIUM. The lower anterior re- 

 gion of the abdomen, from a little below 

 the umbilicus to the pubes. 



HY'POGE^E. (from VTTO and yivo^ai, Gr.) 

 A term applied to rocks, expressing that 

 they have assumed their form, or struc- 

 ture, at a depth from the surface. 



Mr. Lyell, who proposes to give this 

 term to certain rocks, observes, " It will 

 appear that the popular nomenclature of 

 geology, in reference to the so called 

 ' primary' rocks, is not only imperfect, 

 but in a great degree founded on a false 

 theory ; inasmuch as some granites and 

 granitic schists are of origin posterior to 

 many secondary rocks. In other words, 

 some primary formations can already be 

 shown to be newer than many secondary 

 groups, a manifest contradiction in terms." 

 To obviate this difficulty, Mr. Lyell pre- 

 fers the terra hypogene, as one not of 

 chronological import, but implying the 

 theory that such rocks are netherformed, 

 and have not assumed their form and 

 structure at the surface. Principles of 

 Geology. 



HY'STRIX. (varpiZ, Gr.) The porcupine. 



I J 



JA'DE. The Nephrit of Werner ; Neph- 

 rite of Jameson ; called also nephritic 

 stone, nephrite, and axe-stone. It was 

 formerly much celebrated for its supposed 

 medicinal properties in nephritic affec- 

 tions, or diseases of the kidneys. It is 

 found in Hungary and Siberia, America, 

 Egypt, and China. The inhabitants of 

 New Zealand form it into axes, and other 

 cutting instruments, from which circum- 

 stance it has obtained the name of axe- 

 stone. Its surface is smooth ; fracture 

 splintery. It has a greasy feel. Colour 

 dark leek-green. In hardness, jade is, at 

 least, equal to quartz ; it possesses a 

 peculiar tenacity which renders it difficult 

 either to break, cut, or polish. Brochant 

 states its fresh fracture to present a 

 paler green than that of its surface. Be- 

 fore the blow-pipe it fuses easily, and with 

 a slight ebullition, into a bead of white 

 semi-transparent glass. Its analysis is 

 very variously given by different authors ; 

 its constituents are according to some, 

 silica, carbonate of magnesia, iron, alu- 

 mina, carbonate of lime ; others add 



chrome, oxide of manganese, soda, and 

 potassa. In consequence of its tenacity 

 it has been wrought into chains and other 

 delicate works. 



JA'GGED. Irregularly cut or notched, and 

 with the appearance of having been 

 knawed ; denticulated ; uneven ; toothed 

 like a saw. 



JAMB. A term used by miners for a thick 

 bed of stone which prevents their pur- 

 suing a vein. 



JA'MESONITE. A mineral, thus named after 

 Prof. Jameson by Haidinger ; axotomous 

 antimony-glance. It was first discovered 

 in Cornwall, in clay-slate, and it has been 

 since found in Germany and Siberia. Its 

 colour is steel-grey. It consists of lead, 

 antimony, sulphur, and iron. 



JA'NTHINA. (from ianthum, Lat. a violet.) 

 The violet snail. A purple-coloured uni- 

 valve shell, nearly resembling a snail in 

 its form: it is recent, and commonly 

 found in the Mediterranean. The inha"- 

 bitaiits of this shell is said, when irri- 

 tated, to discharge a purple secretion. 



JA'NTHINA FRAGILIS. A species of jan- 



