128 
DISEASES. 
Chap. VI. 
Small-pox and measles passed tlirough 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 travelled inland. For smaU-pox the natives employed in 
some parts inoculation in the forehead with some animal deposit; 
in other parts they employed the matter of the smaU-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 mahgnant confluent form. Where 
the idea came from I cannot conceive. It was practised by the 
Bakwains at a time when they had no intercouse, dmect or indi¬ 
rect, with the southern missionaries. They aU adopt readily the 
use of vaccine vu'us when it is brought within thek reach. 
A certain loathsome disease wliich decimates the North Ame¬ 
rican Indians, and tlu-eatens extu-pation to the South Sea islanders, 
dies out in the interior of Africa without the aid of medicine. 
And the Bangv’^aketse, who brought it from the west coast, lost it 
when they came into their own land south-west of Kolobeng. It 
seems incapable of permanence in any form in persons of pure 
African blood anywhere in the centre of the country. In persons 
of mixed blood it is otherwise; and the vumlence of the secondary 
symptoms seemed to be, in aU the cases that came under my 
care, in exact proportion to the greater or less amount of Euro¬ 
pean 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 pm-e 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 impreg¬ 
nated with sulphate of lime, that kettles quickly become incrusted 
internally with the salt; and some of my patients, who were 
troubled with indigestion, behoved that their stomachs had got 
into the same condition. This freedom from calcuh would appear 
to be remarkable in the Negro race, even in the United States ; 
for seldom indeed have the most famed lithotomists there ever 
operated on a Negro. 
