Major Denham afterwards learned that he had penetrated across Africa as far as Nyffe, on the Niger, where he fell a victim, not to any hostility on the part of the natives, but to disease and the climate.

A young man was even met with, who professed to be his son, though there were some doubt as to the grounds of his claim to that character.
The association, when their expectations from Horneman had failed, began to look round for other adventurers, and there were still a number of active and daring spirits ready to brave the dangers of this undertaking.

Mr.Nicholls, in 1804, repaired to Calabar, in the Gulf of Benin, with the view of penetrating into the interior by this route, which appeared shorter than any other, but without any presentiment that the termination of the Niger was to be found in that quarter.

He was well received by the chiefs on that coast, but could not gain much information respecting that river, being informed that most of the slaves came from the west, and that the navigation of the Calabar stream, at no great distance was interrupted by an immense waterfall, beyond which the surface of the country became very elevated.

Unfortunately, of all the sickly climates of Africa, this is perhaps the most pestilential, and Mr.Nicholls, before commencing his journey, fell a victim to the epidemic fever.
Another German named Roentgen, recommended also by Blumenbach, undertook to penetrate into the interior of Africa by way of Morocco.
He was described as possessing an unblemished character, ardent zeal in the cause, with great strength both of mind and body.