MEN 



461 



M E R 



tensibility and retractility of their upper 

 jaw. 



MKHTH'OUL. Relating to the meningea 

 or membranes of the brain. See MENINX. 



iges, or membranes of the brain or spinal 

 cord. 



ME'NIXX, /wtiyiy-%. A name formerly 

 common to all the membranes of the body, 

 but now appropriated to those of the 

 brain. Plural, meninges. 



MENIS'CUS, Lat. from u,viviffey, a little 

 moon. A lens convex 'on one side, and 

 concave on the other. See LENS. 



MEN ISPER'MIC ACID. An acid obtained 

 from the berries of the Menispermnm coc- 

 ciilus, a shrub which grows in the East 

 Indies. It is an insipid crystalline sub- 

 stance, little soluble in water, and forms 

 with the alkalies and some other bases 

 crystalli/able compounds or menisper- 

 mates. little is known of this acid, or of 

 the salts which it forms. 



MENISPER'MTJM. Moon-seed. A genus 

 of shrubby plants. DiceciaDodectindria. 

 Named from u,r : tr,, the moon, and fTi<u, 

 seed, in allusion to the crescent form of 

 the seeds. The berries of the M. cocculu* 

 are highly poisonous and inebriating, and 

 are supposed to impart that power to 

 most of the London porter. 



MEX'IVER. A small white animal of 

 Russia; also its fur, which is much valued. 



MEN'NONITES. A title of the Anabap- 

 tists of Holland, derived from their leader, 

 Menno. 



MENOBRAN'CHUS. The name given by 

 Harlan to a genus of Batrachians, closely 

 allied to the Tritons or Aquatic Sala- 

 manders. The species most known is the 

 31. lateralis, Harl. , or Triton lateralis, Say. 

 It inhabits the great lakes of North Ame- 

 rica, and attains a length of between two 

 and three feet. 



MENOSS'OMA. The name given by Harlan 

 to a genus of Batrachians, closely allied 

 to the Salamanders. The Hellbender 

 (Salamandra gigantea, Barton), is the best 

 known species. It inhabits the lakes and 

 rivers of the interior of North America. 

 The reptile is about 18 inches long, and 

 of a blackish blue colour. 



MEN'STRUCM. Solvent. All liquids are 

 so called, which are used as dissolvents, 

 infusions, decoctions, &c. The most com- 

 mon is water. The term menstruum is 

 derived from mensts, a month, and its use 

 is supposed to have originated in some 

 notion of the old chemists, about the in- 

 fluence of the moon in the preparation of 

 dissolvents. 



MMSURA'TION, from mensitra, measure. 

 A branch of mathematics which treats of 

 the measurement of the extensions, ca- 

 pacities, solidities, &c. of bodies. 2. 



The result of measuring. 



MES'THA. Hint. An extensive genus ol 

 perennial plants. Didynamia Gymna- 

 spermia. Name from Minthe, who was 

 changed into this herb. Of 41 species, 

 23 are natives of Britain. Among these 

 are the spear-mint, the marsh-mint, the 

 pepper-mint, the bergamot, the water, 

 corn, field, meadow, fen, and broo'E-mint, 

 and the penny-royal or pudding-grass. 



MEN'TUM (Lat.), chin In mammalogy, 

 the anterior and inferior margin of the 

 lower jaw. 



MENU', INSTITUTES or. The most cele- 

 brated code of Indian law, civil and reli- 

 gious; so termed from its author Menu, 

 Menou, or M. 



MENTAN'THES. Buckbean or water-tre- 

 foil. A genus of one species. Petitandria 

 Monogynia. Named from fjt.iv, a month, 

 and attdes , a flower, because it keeps in 

 flower about a month. Europe. 



MENT'NOES. fMivi<y^, membrane. The 

 membranes which cover the brain. 



MEPHIT'IC, from mephitis, an ill smell. 

 Offensive to the smell ; noxious. For- 

 merly carbonic acid was termed mephitic 

 acid and nitrogen, mephitic air. 



MEPHI'TIS, a genus of carnivorous 

 mammalia of the digitigrade tribe th 

 Skunks, remarkable for their horrible 

 foetid exhalations: whence the name me- 

 phitis, an ill smell. The most common 

 species is the American skunk (JU. puto- 

 ritis) somewhat resembling the badger. 



MERCATOR'S CHART. A chart in which 

 the parallels of latitude and the meri- 

 dians are represented by straight lines, 

 invented by Gerard Mcrcator. 



MERCURIA'LIS. Mercury. A genus of 

 plants. IHfcia Enneandria. Named 

 after Mcrcurius, the discoverer of it. 

 There are five species, natives of Eu- 

 rope ; two are British. 



MER'CURY, Lat. Mercurius. 1. The god of 

 eloquence and commerce ; his name i* 

 said to be formed from merces or vttrwr. 

 '2. Quicksilver : a metal which re- 

 mains fluid at ordinary temperatures, but 

 becomes solid, ductile, and malleable 

 when its temperature is reduced 40 de- 

 grees below /ero of Fahrenheit's thermo- 

 meter. It boils at 656 F., and distils off 

 in an elastic vapour, which, being con- 

 densed by cold, forms purified mercury, 

 sp. gr. 13'6, at 60. Its colour is that of 

 pure silver ; it has no taste or smell, com- 

 bines readily with certain metals, as 

 gold, silver, zinc, tin, and bismuth, form- 

 ing mercurial alloys or amalgams. It is 

 this property which makes it so exten- 

 sively useful" in the extraction of gold and 

 silver from their ores, in gilding, pHting, 

 silvering looking-glasses, &c. It occurs. 

 (1.) Native, adhering in small globules to 

 the surface of cinnabar; '*.': In union 

 with silver in the native owii^-'" of til- 



