Whilst serving four years in India, throughout the period of the great mutiny, he assiduously studied oriental dialects, at intervals exploring portions of Java, Thibet, and the Himalayas.
[4] From this period he undertook many journeys of various duration and difficulty, extending from the Arctic regions to the Andes of Ecuador, and from America to the far East, more especially with the object of improving himself in ethnology, botany, and general science.
In 1862 he started from London in the assumed character of an English Muslim gentleman, and, devoid of European contact, proceeded to Cairo, where he lived for a considerable period in the native quarter of the city.
By this time so intimately acquainted had he become with the habits and manners of Islám, that in the spring of the same year he boldly joined the annual Hajj (pilgrimage to Mecca),[5] and successfully accomplished a dangerous exploit which no other Englishman had achieved without disguise of person or of nationality.
But on 14 March 1875, before the manuscripts had received their final corrections, his life was abruptly terminated by disease, induced or hastened by the wear of constant change of climate, exposure in mountain exploration, and by an accident in an attempt to ascend the Matterhorn.