150 
NAT. ORDER. LEGUMNOSiE. 
in the bark, and afterwards hardens in the air. The barks of all the 
species are hig-hly astring-ent, and some are used in India for tanning'. 
There are two kinds of gum found in the shops in this country, and 
often sold promiscuously, but distingxiished in commerce by the names 
of g'um-arabic and East India g-um. Gum-arabic consists of roundish 
transparent tears, colorless, or of a yellowish color, without smell or 
taste, and almost perfectly soluble in water. The pieces which are 
most transparent, and have least color, are reckoned the best. They 
are sometimes separated from the gum-arabic, and sold for about 
double the price, under the name of picked g'um. The East India 
gum is darker colored than gum-arabic, and is not so readily soluble in 
water. Gum-thur, the produce of Acacia Arabic, is almost colorless, 
and resembles the picked gum, and gum-senegal resembles the East 
India gum. 
About the middle of November, that is, after the rainy season, 
which begins early in July, a gummy juice exudes spontaneously from 
the trunk and principal branches. In about fifteen days it thickens in 
the furrow down which it runs, either into a vermicular shape, or more 
commonly assuming the form of round or oval tears, about the size of 
a p'g'eon's egg, of different color, as they belong to the white or red 
gum tree. About the middle of December, the Moors encamp on the 
borders of the forests, and the harvest lasts five weeks. The gum is 
packed in very large sacks of tanned leather, and brought on camels 
and bullocks to certain ports, where it is sold to the French and Eng- 
lish merchants. Mr. Jackson, in his account of the Empire of Moroc- 
co, informs us that from Mogodor they export two sorts of gum, one is 
common gum-arabic, the other finer, called gum-soudan, brought from 
Tumbucto by the caravans. He also says that the gum called Mo- 
rocco or Barbary-gum, is produced from a thorny tree called Attabeli. 
It yields most gum during the parching heat of July and August, and 
the hotter the weather, and the more sickly the tree appears, the more 
gum it yields. 
The gum is highly nutritious. During the whole time of the gum 
