436 VEGETABLE SUBSTANCES. 



by exposure to the air in a similar manner to the 

 gum which is often produced from the cherry and 

 some other trees growing in this country. When the 

 tree first opens its flowers the gum begins to flow, 

 and continues to exude during the rainy season, until 

 the month of December. It is then collected for the 

 first time. In the month of March incisions are made 

 in the bark, an operation rendered necessary, it is said, 

 by the extreme dryness of the weather, and the gum 

 issuing from these wounds is soon after collected. 



Gum arabic is imported into this country from 

 the East Indies, Turkey, and Africa. The East- 

 Indian is the worst. It is distinguished in commerce 

 by its colour, the lightest being most esteemed ; its 

 price is from 2. 2v. to 12. 12s. according to its 

 quality. The quantity retained for home consumption 

 in 1830 was 12,193 cwt. It is admitted under a 

 duty of 6s. per cwt. from British possessions, the duty 

 being doubled on that coming from foreign countries. 



Gum Senegal is extremely similar to gum arabic, 

 though of rather an inferior quality. It is the pro- 

 duct of another species of acacia. The Senegal 

 mimosa is a native of Guinea. Its flowers are yellow, 

 globular, and fragrant ; the pods are brown, rounder, 

 and smaller than those of the nilotica. On incisions 

 being made in the bark of the tree, the gum exudes 

 but less plentifully than the gum arabic. 



It is likewise not so transparent and is of a darker 

 colour. This gum is much used for all those pur- 

 poses to which gum arabic is applied. It is subject 

 to the same rate of duty as gum arabic ; its price is 

 from ,3. 16s. to 4. 4s. per cwt. The quantity 

 reserved for home consumption for 1830 was 3,493 

 cwt. It is imported from Senegal and Barbary. 



The Astragalus tragacantha, a small prickly shrub 

 jiot exceeding three feet in height, growing in many 



