406 



THE LAKE REGIONS OF CENTRAL AFRICA. 



a piece of 35 lbs. is shown. Lastly, the gum is thrown broad- 

 cast into boxes and exported from the island. The Hamburg 

 merchants keep European coopers, who put together the cases 

 whose material is sent out to them. It is almost impossible to 

 average the export of copal from Zanzibar. According to the 

 late Lieutenant-Colonel Hamerton, it varies from 800,000 to 

 1,200,000 lbs. per annum, of which Hamburg absorbs 150,000 

 lbs., and Bombay two lacs' worth. The refuse copal used for- 

 merly to reach India as " packing," being deemed of no value in 

 commerce ; of late years the scarcity of the supply has rendered 

 merchants more careful. The price, also, is subject to incessant 

 fluctuations, and during the last few years it has increased from 

 4 dol. 50 cents to a maximum of 12 dollars per frasilah. 



According to the Arabs, the redder the soil the better is the 

 copal. The superficies of the copal country is generally a thin 

 coat of white sand, covering a dark and fertilising humus, the 

 vestiges of decayed vegetation, which varies from a few inches 

 to a foot and a half in depth. In the island of Zanzibar, which 

 produces only the chakazi or raw copal, the subsoil is a stiff blue 

 clay, the raised sea-beach, and the ancient habitat of the coco. 

 It becomes greasy and adhesive, clogging the hoe in its lower 

 bed ; where it is dotted with blood-coloured fragments of ochreish 

 earth, proving the presence of oxidising and chalybeate efficients, 

 and with a fibrous light-red matter, apparently decayed coco- 

 roots. At a depth of from 2 to 3 feet water oozes from the 

 greasy walls of the pit. When digging through these formations, 

 the gum copal occurs in the vegetable soil overlying the clayey 

 subsoil. 



A visit to the little port of Saadani afforded different results. 

 After crossing 3 miles of alluvial and maritime plain, covered 

 with a rank vegetation of spear grass and low thorns, with occa- 

 sional mimosas and tall hyphsenas, which have supplanted the 

 coco, the traveller finds a few scattered specimens of the living 

 tree and pits dotting the ground. The diggers, however, ge- 

 nerally advance another mile to a distinctly formed sea-beach, 

 marked with lateral bands of quartzose and water-rolled pebbles, 

 and swelling gradually to 150 feet from the alluvial plain. The 

 thin but rich vegetable covering supports a luxuriant thicket, 

 the subsoil is red and sandy, and the colour darkens as the 

 excavation deepens. After 3 feet, fibrous matter appears, and 

 below this copal, dusty and comminuted, is blended with the red 

 ochreish earth. The guides assert that they have never hit upon 

 the subsoil of blue clay, but they never dig lower than a man's 

 waist, and the pits are seldom more than 2 feet in depth. Though 



