Where the idea came from I can not conceive.

It was practiced by the Bakwains at a time when they had no intercourse, direct or indirect, with the southern missionaries.

They all adopt readily the use of vaccine virus when it is brought within their reach.
A certain loathsome disease, which decimates the North American Indians, and threatens extirpation to the South Sea Islanders, dies out in the interior of Africa without the aid of medicine; and the Bangwaketse, who brought it from the west coast, lost it when they came into their own land southwest of Kolobeng.

It seems incapable of permanence in any form in persons of pure African blood any where in the centre of the country.
In persons of mixed blood it is otherwise; and the virulence of the secondary symptoms seemed to be, in all the cases that came under my care, in exact proportion to the greater or less amount of European blood in the patient.

Among the Corannas and Griquas of mixed breed it produces the same ravages as in Europe; among half-blood Portuguese it is equally frightful in its inroads on the system; but in the pure Negro of the central parts it is quite incapable of permanence.