ivy 



JEJ 



amounting to 11^° of latitude. In 

 passing over the American continent 

 they again recede to the northward ; 

 and in California, and to tlie north 

 of that peninsula, along the western 

 side of the continent, the annual tem- 

 perature is nearly the same as under 

 similar latitudes in the west of Eu- 

 rope. From the western to the east- 

 ern side of the old continent, the flex- 

 ure of the isothermal curves and the 

 diminution of the mean annual tem- 

 perature under the same parallels 

 are not less conspicuous. The iso- 

 thermal line of 55=" passes through 

 Nantes, lat. 47°, and Pekin, lat. 39^. 

 Edinburgh and Kasan (in the east of 

 Russia) have the same latitude ; but 

 the mean annual temperature of the 

 former is 48°, while that of the sec- 

 ond is below 38°." 



ISSUE. In farriery, an artificial 

 ulcer, made by cutting through the 

 skin and inserting a pea or smooth 

 stone in the wound ; it is to be care- 

 fully dressed and washed daily. It 

 is a means of establishing a local ir- 

 ritation to relieve some important 

 organ, as the eye. 



ITALIAN RYE GRASS. Lolium 

 perenne. See Grasses. 



ITCH. A disease of the skin, in 

 which small vesicles are produced in 

 the angles of the body by the irrita- 

 tion of an insect. It is cured by an 

 ointment of sulphur applied daily. It 

 is sometimes called mange in farriery. 



lULUS. The generic name of the 

 gaily worm ; insects with numerous 

 feet (rmjriapoda). 



IVORY. The compact bony struc- 

 ture of the tusks of elephants ; it con- 

 tains G6 per cent, bone earth and 24 

 gelatin. 



IVORY BLACK. Bone black. 



IVY. Hedera helix. A hardy ev- 

 ergreen climbing shrub, used for rus- 

 tic coverings : it kills trees. It is 

 readily propagated by cuttings, and 

 once trained to a wall, will hold on 

 by its own branch roots. The Vir- 

 ginian creeper is sometimes called 

 American ivy, but in no way resem- 

 bles true ivv. 



IVY, I R I S H ( Canatiensis). ' ' A 

 fast-growing climber, with large lobed 

 444 



leaves, which soon covers walls and 

 houses. It is propagated by layers, 

 or slips taken off and planted where 

 they are to grow." — {Johnson.) 



J. 



JACK. A general name given to 

 engines for raising heavy weights, as 

 well as some used for turning spits, 

 (Sec. 



JACKDAW. A species of crow 

 {Corvus monedula.) 



JACK TIMBERS. Those in a bay 

 of timbers which are shorter than the 

 rest. 



JACOB'S LADDER. Polemonmm 

 ccrideum. A common flower. 



JACOB'S STAFF. The cross 

 staff used by surveyors in measuring 

 heights and distances. 



JADE. Nephrite. 



JALAP. The root of the Ipomcea 

 jalapa, a convolvulaceous, Mexican 

 plant, which might be readily cultiva- 

 ted in the Southern .States. It climbs, 

 and has a perennial root, or tuber, 

 which is large enough for the market 

 in three years. It is a powerful purge, 

 the dose being ten to twenty grains 

 for a man. 



JAMAICA PEPPER. Myrtus pi- 

 mcnta. Allspice, the produce of an 

 evergreen tree of tropical America. 

 The berries are warm and aromatic. 



JAMBS. The sides or posts of 

 any aperture or door which bear the 

 cross piece on which the weight of 

 the wall rests. 



JAMESTOWN WEED. Datura 

 stramonium. A poisonous weed. See 

 Stramonium. 



J.ASPER. An ornamental and col- 

 oured silicious mineral. 



JATROPA. A genus of euphor- 

 beous, tropical plants, of which the 

 J. Manihot yields a root from which 

 cassava is extracted ; the J. curcas, 

 purging seeds resembling castor oil 

 seeds. 



JAUNDICE. A disease in which 

 the biliary secretion is much changed, 

 the skin coloured yellow, with much 

 lassitude. 



JEFFERSONITE. A kind of au- 

 gite. 



JEJUNUM. The portion of tho 



