In the desert, he informs his friend Watt that no fewer than thirty-two edible roots and forty-three fruits grew without cultivation.

He had the rare faculty of directing his mind at the full stretch of its power to one great object, and yet, apparently without effort, giving minute and most careful attention to many other matters,--all bearing, however, on the same great end.
A very interesting letter to Dr.Risdon Bennett, dated Kuruman, 18th December, 1841, gives an account of his first year's work from the medical and scientific point of view.

First, he gives an amusing picture of the Bechuana chiefs, and then some details of his medical practice: The people are all under the feudal system of government, the chieftainship is hereditary, and although the chief is usually the greatest ass, and the most insignificant of the tribe in appearance, the people pay a deference to him which is truly astonishing....

I feel the benefit often of your instructions, and of those I got through your kindness.

Here I have an immense practice.