Thanks to the well-known courtesy of M. Malte-Brun, then the editor of the "_Annales des Voyages_," and a corresponding member of all the Geographical Societies of Europe, as well as a friend of all the great explorers in the world, M. Delange obtained some very valuable information as to the diseases against which he would have to use his skill in Africa, the precautions to be taken to steer clear of them, and the various remedies best suited to the different districts and climates. He also devoted himself, more seriously than he had hitherto done, to the study of Natural History, hoping soon to be able to do good service to that branch of science. Dr. Desrioux, by way of pleasing Madame de Guéran, placed his services at the disposal of his _confrère_. He thought of everything, was ever on the watch, and made many suggestions, the value of which, later on and in time of peril, was amply proved. Although he could not leave Paris, he was as deeply interested in everything connected with the projected expedition, as if he were going to form part of it—he was, in fact, its soul. As for Joseph, he had been beside himself with joy ever since the memorable day when he was informed that he was to take part in the expedition. At last his dreams were about to be realized—an Arab name, a bûrnus, a camel! As for the name, he assumed it at once, without any tender regret for the one he had hitherto borne. At all the shops where he made his purely personal purchases, he gave as his address—Mohammed-Abd-el-Gazal. It appeared to him decidedly more _distingué_ than Joseph, and imbued him with an Eastern tinge. The camel—well, unfortunately, he would have to wait for that. But when M. de Morin gave him a holiday to say good-bye to his family, Joseph allowed his relatives to slide, as the Americans say, and betook himself to the _Jardin des Plantes_ to gaze on the camels, and study their habits. He even succeeded in inducing one of the keepers to let him lay a tenderly caressing hand on one of those noble coursers of the desert, or as Joseph, ever high-sounding and figurative, would call them, those placid beasts. Neither did he lose any time in becoming the proud possessor of the most correct and ample of bûrnus, this national garment having been willingly surrendered to him by an Arab servant, whose master was then staying at the Grand-Hôtel. Joseph was perpetually, night and day, trying on this bûrnus, and when he had draped it round him he would solemnly walk up and down his room in the Rue Taitbout. M. de Morin, who had not been apprized of this new caprice of his servant, and was, consequently, not prepared for the metamorphosis, thought, when he returned home one evening, that his rooms were frequented by ghosts.