JAG 



405 



J A N 



JACK-OF-THE-CI.OCK-HOUSE, a figure of a 

 little man, which strikes the quarters in 

 gome clocks. 



jACK-OF-THE-LANTEUN.Win-of-the-WiSp. 



Vulgar names for the ignis fatwis. 



JACK-PLANE, a plane of about 18 inches 

 long, to prepare wood for the trying-plane. 

 JACK'RAFTERS. In joinery, the jack- 

 timbers which are fastened to the high 

 rafters and the wall-plates. 



JACK'RIBS. In joinery, the jack-timbers 

 which are fastened to the angle-ribs, and 

 rest upon the wall-plates in groined or 

 domed ceilings. 



JACKS. Wooden wedges used in coal- 

 mines. 



JACK'SIJJKERS. Parts of a stocking-frame. 

 JACK'TIMBER. In joinery, a short tim- 

 ber fastened at the ends of two timbers 

 which are not parallel, or to two timbers 

 which actually meet in a point, as to the 

 wall-plate and hip-rafter of a roof, the 

 wall-plate and hip of a groin, &c. 



JAC'OBINS. In French history, a political 

 club, which bore a well-known part in 

 the first Revolution. In ecclesiastical his- 

 tory, the French appellation of the reli- 

 gious order of St. Dominic. 



JAC'OBITES. 1. In English history, the 

 adherents of James II., after his abdica- 

 tion. 2. In church history, certain Sy- 

 rian Christians, who hold that Christ had 

 but one nature, and practise both circum- 

 cision and baptism. 



JA'COB'S LADDER. In naval off airs, a rope- 

 ladder with wooden spokes. 



JA'COB'S STAFF, a mathematical instru- 

 ment for taking heights and distances. A 

 kind of astrolabe, or cross-staff, much 

 used in the middle ages. 



JACO'BCS, Lat. for James. A gold coin 

 of the reign of James I. ; value 25s. 



JAC'ONET, a muslin fabric finer than 

 causey, and coarser than lawn. 



JACQCARD LOOM, a peculiar and most 

 ingenious mechanism, invented by M. 

 Jacquart, of Lyons, in 1800, to be adapted 

 to a silk or muslin loom, to supersede the 

 use of drawboys in weaving figured goods. 

 It has of late been extensively applied in 

 the weaving of carpets. 



JAC'QUERIE. In French history, the name 

 given to a revolt of the peasantry against 

 the nobility, in 1356. 



JACTITA'TION, fromjactito. A term, in 

 canon law, for a false pretension to mar- 

 riage. 



JADE, a hard magnesian mineral, called 

 also nephrite, nephritic stone, and axe- 

 stone. See AXESTONE. In consequence of 

 its tenacity it has been wrought into 

 chains and other delicate works. The name 

 has been supposed to originate from igida, 

 the Indian name of the stone. 



JAOU'RT . In commerce, a Bengalese name 

 for a species of coarse sugar in an impure 



JAOHIRE', an East Indian word, denot- 

 ng an assignment of the government 

 share of the produce of a portion of land 

 to an individual, either personal, or for 

 the support of a public establishment, 

 particularly of a military nature. The 

 holder of a jaghire is styled ajaghire dar. 



JAGUAR'. In zoology, the tiger of the 

 Brazils. It is about the size of a wolf, 

 very fierce and destructive among the 



rger quadrupeds, as oxen, horses, sheep, 

 &c. 



JAL'AP or JALOP, the root of the Convol- 

 vulus jalapa, an herbaceous twining vine ; 

 so named from Xalapa, in Mexico, from 

 which it is chiefly imported. The root is 

 only used in medicine. 



~AL'APINE or JALAPPIN, resin of jalap. 

 The active principle of jalap, obtained by 

 digesting that root in alcohol. Herberger 

 considers it an alkaloid, but its alkaline 

 properties are not well established. 



JAMACI'NA, a vegeto-alkaline principle 

 discovered in 1824 by M. Huttenschmidt 

 in the bark of the Geoffroya jantaicensis. 

 or cabbage-bark tree. It crystallised 

 from its aqueous solutions. 



JAMAI'CA BARK, the bark of the Cin- 

 chona Caribaa,^ or Caribaean bark-tree, 

 which grows in Jamaica, where it is 

 called the sea-side beech. 



JAMAI'CA PEP'PER, the fruit of the Myr- 

 tus pimento, or allspice tree. See PIMENTO. 



jAMB,Fr.jow6e, a leg. 1. Among min- 

 er*, a thick bed of stone which hinders 

 them in pursuing a vein. 2. In archi- 

 tecture, a supporter. Door-posts, upright 

 posts at the ends of window-frames, the 

 upright sides of a fire-place from the 

 hearth to the mantle-piece, are all termed 

 jambs ; the uprights on the sides of door- 

 ways are more particularly called jamb- 

 posts, and the side-work attached is termed 



jamb-lining. 3. A sea term ; to squeeze 



tight. 



JAMES, ORDER OF THE SWORD or SAINT, 

 an ancient military order in Spain and 

 Portugal. 



JAMES'S FIMS, pills made of equal parts 

 of James's powder, ammoniacum, and the 

 aloes and myrrh pill, beat up with tinc- 

 ture of castor. 



JAMES'S POWDER, an antimonial medi- 

 cine invented by Dr. James, and termed 

 by him fever powder, being used by him 

 extensively in fever cases. It still retains 

 much of its reputation. 



JAN'ITOR (Lat.). 1. A door or gate- 

 keeper, tramjamia, a gate. 2. In ana- 

 tomy, the pylorus, situated at the entrance 

 of the intestine. 



JANE. 1. A coin of Genoa. 2. A sort 



of fustian. 



JAN'IZARIES, corrupted from the Turkish 

 Teniskeri, new troops. A name for the 

 Turkish infantry ; reputed the Grand 

 Seignor's guards. Now abolished. 



