VEGETABLE PRODUCTS. 



149 



Its colour is yellow, and taste nauseous. It is 

 used sometimes in medicine. 



Scammont/. . This sutstance is the produce of 

 the convolvulus scammonia, a climbing plant which 

 gTows in Persia. The root when cut yields a 

 milky juice by expression, which, when it con- 

 cretes, forms scammony. Its colour is dark gi'ay, 

 its smell nauseous when rubbed, and its taste 

 bitter. It forms with water a green opaque 

 liquid. It is much employed in medicine, and 

 operates as a strong purgative. 



Opoponax. The plant from which this sub- 

 stance is obtained, is the pastinacea opoponax, 

 a native of the countries of the Levant. It 

 exudes in the state of a milky juice, from in- 

 cisions made in the root. It is afterwards dried 

 in the sun, and is generally to be met with in 

 lumps of a reddish colour, and white within. 

 Its taste is bitter and acrid, and it forms with 

 water a milky solution. 



Euphorlium. This substance is the produce 

 of the euphorbia officinalis, a plant which grows 

 in Africa. It is the milky juice of the plant 

 dried in the sun, and obtained by means of in- 

 cisions. It assumes the form of small yellow 

 tears. It has no smeU, its taste is caustic. It 

 is poisonous, but is occasionally employed in 

 medicine. 



Olihanum. This substance is obtained from 

 the juniperus lycia, which grows in Arabia, par- 

 ticularly by the borders of the Red sea. It is 

 the frankincense of the ancients. It exudes 

 from incisions made in the tree, and concretes 

 into masses about the size of a chestnut. It is 

 brittle, transparent, and of a yellow colour. It 

 has little taste, but when burnt diffuses an 

 agi-eeable odour. 



Sagapenum. The plant from which this sub- 

 stance is obtained is not well knovsm; but it is 

 supposed to be the ferula Persica, The sub- 

 stance itself is brought from Egypt, Persia, or 

 India. It is generally in the form of agglutin- 

 ated tears. Its colour is yellow, its taste hot 

 and bitter, and its siiiell alliaceous. 



Gamboge is the produce of the mangostana 

 cainbogia,a. tree which grows in the East Indies. 

 It exudes from incisions of the bark, and is 

 brought to Europe in large cakes or cylindrical 

 masses. Its colour is yeUow, and its fracture 

 vitrious; but it has no smell and very little 

 taste. It forms with water a yellow turbid 

 liquid, but is soluble almost entirely in alcohol. 

 In medicine it is a strong purgative. It is much 

 used as a pigment. , 



Myrrh. This substance is procured from a 

 tree which grows in Abyssinia and Arabia; the 

 real species of which has not yet been ascertained. 

 According to Bruce it belongs to the mimosa. 

 It exudes from the tree in the state of a yel- 

 lowish white liquid, which soon concretes into 

 a solid substance. The best is transparent, and 



has a reddish brown colour. Its odour is strong 

 and peculiar, its taste bitter and aromatic. It 

 does not melt when heated, and burns with dif- 

 ficulty. It is occasionally used in medicine, and 

 as a dentifrice. 



Asafcetida. This substance, so well charac- 

 terised by its strong and foetid smell, is obtained 

 from the ferula asafcetida, a plant which grows 

 in Persia. At four years old the plant is dug 

 up by the root; the root is then cleaned and the 

 extremity cut off; a milky juice exudes, which 

 is collected; and when it ceases to flow another 

 portion is cut off and more juice extricated. The 

 process is continued till the root is exhausted. 

 The juice which has been collected soon con- 

 cretes, and constitutes asafcetida. It is brought 

 to Europe in small agglutinated grains of differ- 

 ent colours: white, red, and yellow. It is hard 

 but brittle. Its taste is bitter, and its smeU in- 

 sufferably foetid; and yet the Indians use it as 

 a seasoning for their food, and call it the food of 

 the gods. This forms a strong contrast to the 

 name it has obtained in Europe, where it is vul- 

 garly known by the appellation of devil's dung. 

 It is used in medicine. 



Aloes. Strictly speaking, aloes hardly belongs 

 to the gum resins; but as it often exudes spon- 

 taneously from the leaves when the point of 

 these is cut off, and afterwards gradually con- 

 cretes into a solid mass, the analogy is so close 

 as to warrant its insertion here. 



Two kinds of aloes occur in commerce, Soco- 

 tara aloes, and Barbadoes aloes. The first kind 

 came originally from Socotora, an island at the 

 entrance of the Red sea; but of late years this 

 country is almost entirely supplied with aloes 

 from Bombay. The plant which yields this 

 variety is the aloe spicata. The leaves are cut 

 off close to the stem, then cut in pieces, and their 

 juice allowed to run out; after a sediment has 

 subsided the clear liquid is allowed to concrete 

 in the sun. The taste of aloes is entirely bitter; 

 it is soluble in alcohol and water, and is much 

 used in medicine as a purgative. 



Balsams. The substances known by the name 

 of balsams are nearly related to the resins and 

 gum resins. They all contain benzoic acid. 

 They are obtained by incisions made in the bark, 

 from which a viscous juice flows, which is after- 

 wards thickened by exposure to the sun or a 

 fire; or they are obtained by boiling the part of 

 the tree containing them. They are thick and 

 viscid juices, but become readily concrete; their 

 colour is brown or red; their smell aromatic when 

 rubbed; their taste acrid. They are insoluble in 

 water, but boiling water extracts part of their 

 acid; they are soluble in the alkalies and nitric 

 acid. When heated they melt and swell, evolv- 

 ing a white and odorous smoke. 



Benzoin. It was long supposed that this sub- 

 stance was the produce of a species of laurusi 



