No individual or animal got the complaint
by inoculation from the animals' teeth; and from all that I could hear,
the prevailing idea of hydrophobia not existing within the tropics
seems to be quite correct.
The diseases known among the Bakwains are remarkably few.
There is no consumption nor scrofula, and insanity and hydrocephalus are rare.
Cancer and cholera are quite unknown. Small-pox and measles passed
through the country about twenty years ago, and committed great ravages;
but, though the former has since broken out on the coast repeatedly,
neither disease has since traveled inland. For small-pox,
the natives employed, in some parts, inoculation in the forehead
with some animal deposit; in other parts, they employed
the matter of the small-pox itself; and in one village they seem
to have selected a virulent case for the matter used in the operation,
for nearly all the village was swept off by the disease
in a malignant confluent form. 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. Among the Barotse
I found a disease called manassah, which closely resembles
that of the `foeda mulier' of history.
Equally unknown is stone in the bladder and gravel. I never met with a case,
though the waters are often so strongly impregnated with sulphate of lime
that kettles quickly become incrusted internally with the salt;
and some of my patients, who were troubled with indigestion, believed that
their stomachs had got into the same condition.
