The corallines of the coast are of course destitute of metals. A story is told of an ingenious Frenchman who, wishing to become Director of Mines in the service of H. H. the Sayyid, melted down a few dollars, and ran a. vein of silver, most unfortunately, into a mass of madrepore: the curious ‘gangue’ was shown to Lieutenant-Colonel Hamerton, and thus the ’cute experiment failed. The African interior beyond the mountains is rich in copper and iron. I have described the copper of the Taganyika Lake Region: it is said to be collected in small nuggets from torrent- beds, and the bars have evidently been cast in sand. The iron of the Umasai country makes the finest steel. Gold has undoubtedly been brought from the mountains of Chaga; and the eastern plateau promises to rival in auriferous wealth the Gold Coast. The great fields north of and near the Zambeze, and N. West of Natal, beyond the Transvaal Republic, discovered in 1866-7 by the German explorer, M. Mauch, a country consisting of metamorphic rocks and auriferous quartz, will probably be found extending high up in East Africa throughout the rocks lying inland of the maritime and sub- maritime corallines. It is also likely that the vast coal-beds, explored by the Portuguese, and visited by Dr Livingstone, in the vicinity of Tete on the Zambeze, and afterwards prolonged by him to the Rufuma river, a formation quite unknown to our popular works, will be extended to the Zanzibar coast. The valleys of rivers falling into the Indian Ocean should be carefully examined. The similarity of climate and geographical position which the province of São Paulo, and indeed the maritime regions of the Brazil generally, present with Eastern Africa, first drew my attention to its vast and various carboniferous deposits, and they are found to correspond with those of the Dark Continent. Messrs Rebmann and Pollock visited a spot near the ‘Water of Doruma,’ in the Rabai Range, near Mombasah, where antimony[65] is dug. They found no excavations, but the people told them to return after the rains, when the ground would be soft. The holes, they say, were rarely deeper than a foot and a half. Captain Guillain (iii. 277) was told that near the village ‘M’tchiokara’ ‘il existe, presque à fleur de terre, des amas d’une substance métallifère, qui semblerait être un antimoniure d’argent, autant qu’il a été permis d’en juger par les échantillons donnés à nos voyageurs.’