We were in a deep gorge on a steep knoll bounded by a ravine about sixty feet of perpendicular depth, at the bottom of which flowed a torrent. This was an excellent spot for a camp, as no guards were necessary upon the side thus protected. Bordering the ravine were a number of fine trees covered with a thorny stem creeper, with leaves much resembling those of a species of yam. These were at once pronounced by Ibrahimawa to be a perfect god-send, and after a few minutes' grubbing he produced a basketful of fine-looking yams. In an instant this display of food attracted a crowd of hungry people, including those of Ibrahim and my own men, who, not being botanists, had left the search for food to Ibrahimawa, but who determined to share the tempting results. A rush was made at his basket, which was emptied on the instant; and I am sorry to confess that the black angel Saat was one of the first to seize three or four of the largest yams, which he most unceremoniously put in a pot and deliberately cooked as though he had been the botanical discoverer. How often the original discoverer suffers, while others benefit from his labours! Ibrahimawa, the scientific botanist, was left without a yam, after all his labour of grubbing up a basketful. Pots were boiling in all directions, and a feast in store for the hungry men who had marched twenty miles without eating since the morning. The yams were cooked; but I did not like the look of them, and seeing that the multitude were ready, I determined to reserve a few for our own eating should they be generally pronounced good. The men ate them voraciously. Hardly ten minutes had elapsed from the commencement of the feast when first one and then another disappeared, and from a distance I heard a smothered but unmistakeable sound, that reminded me of the lurching effect of a channel steamer upon a crowd of passengers. Presently the boy Saat showed symptoms of distress, and vanished from our presence; and all those that had dined off Ibrahimawa's botanical specimens were suffering from a most powerful "vomi-purgatif." The angels that watch over scientific botanists had preserved Ibrahimawa from all evil. He had discovered the yams, and the men had stolen them from him; they enjoyed the fruits, while he gained an experience invaluable at their expense. I was quite contented to have waited until others had tried them before I made the experiment. Many of the yam tribe are poisonous; there is one variety much liked at Obbo, but which is deadly in its effects should it be eaten without a certain preparation. It is first scraped, and then soaked in a running stream for a fortnight. It is then cut into thin slices, and dried in the sun until quite crisp; by this means it is rendered harmless. The dried slices are stored for use; and they are generally pounded in a mortar into flour, and used as a kind of porridge.