The next letter in the series is addressed to his sister, from “Mourzuk, August 6, 1822;” and though both it, and the one which follows to Professor Jameson, relate to the Doctor’s excursion to Ghaat, or the Tuarick country, of which an account is given in the “Narrative of Travels and Discoveries,” made by the mission, published by Major D. Denham and Captain H. Clapperton, in 1826; yet, as they contain some interesting particulars which will not be found in the “Narrative,” our readers, we trust, will thank us for inserting them in this biographical memoir. In the letter to his sister, he says,— “My worthy friend Clapperton and I have been busily engaged ever since our arrival here. Within the last two months we have been travelling much, and have examined to the extent of at least 800 miles of country. We experienced little fatigue, and in place of being weakened, our health has been greatly improved. We have been among the Tuaricks, and have been treated by that independent and curious people with the greatest kindness and hospitality. They occupy all that dreary waste which you see in the maps called the ‘Great Sahara,’ and live on the milk and flesh of their camels. The care of these animals, and occasional excursions upon the neighbouring states, are their principal occupation. They are a superstitious race; but have good sense withal. They were so much our friends, that we might have travelled, in perfect safety, over the whole of their dominions.” TO PROFESSOR JAMESON. “_Mourzuk, September 17_, 1822.