346 



The World's Commercial Products 



begin to exude gum in the 

 third year of growth, when 

 they are from eight to ten 

 feet high, and have a maxi- 

 mum girth of from six to 

 eight inches. They continue 

 to produce gum until the 

 fifteenth year, when it is 

 advisable to renew them. 

 The best yields are obtained 

 from the eighth to the 

 twelfth years of growth. 



"Hashab Wady" is the 

 name applied to gum which 

 is exuded naturally from 

 "hashab" trees not in- 

 cluded in the " genena," 

 and is usually in • pear- 

 shaped pieces of ' variable 

 size depending on the length 

 of time between consecutive 

 pickings. 



Most Of the gum exported 

 is merely cleaned, but a 

 small quantity is " selected " 

 and " specially dried." For 

 this purpose nearly colour- 

 less " tears " are selected 

 from the crude " hashab'' 

 and exposed on the sand 

 along the banks of the Nile 

 to the sun. After a few 

 days of this treatment they 

 become white and almost opaque, due to the production of innumerable cracks as the result of 

 the drying. This gum fetches a higher price than the crude mixed material. 



For most purposes to which gum is applied in commerce, the crude unselected " hashab " 

 is suitable, but for a few purposes " graded " or " selected " gum is required. The " selection " 

 of gum is principally done in European centres of trade, such as Trieste, London, and Hamburg. 



Senegal Gum. 



The " hashab ". tree- (Acacia Senegal), from which Sudanese gum is principally derived, 

 occurs right through the fertile belt of territory (the Central and Western Sudan), which 

 stretches across Africa below the Sahara. On the north bank of the Senegal vast forests of 

 Acacia Senegal occur stretching away into the hinterland. This region is inhabited by Moors 

 and other wandering peoples who employ their slaves and probably also their prisoners of war 

 in the collection of gum. No system of cultivation such as that adopted in the " genenas " 

 of Kordofan is attempted in Senegambia or its hinterland. During the rains the forests are 

 converted into swamps and "the trees become gorged with sap. After the rains have ceased 

 the scorching east wind known as the Harmattan prevails, and this rapidly removes the excess 

 of water ; the barks of the trees become fissured in all directions and through these fissures 

 the gum exudes as a thick liquid, which rapidly dries into " tears." 



From Stereograph Copyright, Underwood & Underwood, London and New York 



DISTILLING TURPENTINE, NORTH CAROLINA 



