ALOES TREE. 191 



lie adopts the opinions of Ray and Miller, in considering it a Con. 

 volvulus ; and indeed after the account of this plant given by Dr. 

 Houston, we are surprised that any doubt should still remain upon 

 this subject. 



It is said that the root of Jalap was first brought to Europe about 

 the year lfjlO, and took its name from Xalapa, a province or town 

 in New Spain. In the shops we find this root botli cut into slices, 

 and whole, of an oval shape, solid, ponderous, blackish on the out- 

 side, but grey within, and marked with several dark veins, by the 

 number of which, and by its hardness, heaviness, and dark colour, 

 the goodness of the root is to be estimated. It ha3 scarcely any smell, 

 and very little taste, but to the tongue and to the throat manifests 

 a slight degree of pungency. The medicinal activity of Jalap resides 

 principally, if not wholly, in the resin, which though given in small 

 doses, occasions violent tormina. The gummy part bears an incon- 

 siderable proportion to the resinous, and is found to have little or 

 no cathartic power, but as a diuretic it is extremely active. That 

 Jalap is an efficacious and safe purgative daily experience must 

 evince, but according as the root contains more or less resin, its 

 effects must of course vary. Hoffman thought it particularly im- 

 proper and unsafe to administer this medicine to children ; but Dr. 

 Cullen observes, that if Jalap " be well triturated before exhibition 

 with a hard powder, and the crystals of tartar are the fittest for the 

 purpose, it will operate in lesser doses than when taken by itself, 

 and at the same time very moderately and without griping." 



[Linn. Hay. North. WoodvilU. 



section xx. 



Aloes Tree. 

 Aloe Spicata. Sibthorp. 

 Seven species belong to this genus, some of them yielding a 

 warm, purgative gum. Tlie root of the species before us is peren- 

 nial, strong, fibrous : the flower.stems rise three or four feet in 

 height, and are smooth, erect, of a glaucous green colour, and to. 

 wards the top beset with ovate bracteal scales: the leaves are nu- 

 merous, and proceed from the upper part of the root : they are 

 narrow, tapering, thick, or fleshy, succulent, smooth, glaucous, and 



