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.  This freedom from calculi 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.

The diseases most prevalent are the following:  pneumonia, produced by sudden changes of temperature, and other inflammations, as of the bowels, stomach, and pleura; rheumatism; disease of the heart—­but these become rare as the people adopt the European dress—­various forms of indigestion and ophthalmia; hooping-cough comes frequently; and every year the period preceding the rains is marked by some sort of epidemic.  Sometimes it is general ophthalmia, resembling closely the Egyptian.  In another year it is a kind of diarrhoea, which nothing will cure until there is a fall of rain, and any thing acts as a charm after that.  One year the epidemic period was marked by a disease which looked like pneumonia, but had the peculiar symptom strongly developed of great pain in the seventh cervical process.  Many persons died of it, after being in a comatose state for many hours or days before their decease.  No inspection of the body being ever allowed by these people, and the place of sepulture being carefully concealed, I had to rest satisfied with conjecture.  Frequently the Bakwains buried their dead in the huts where they died, for fear lest the witches (Baloi) should disinter their friends, and use some part of the body in their fiendish arts.  Scarcely is the breath out of the body when the unfortunate patient is hurried away to be buried.  An ant-eater’s hole is often selected, in order to save the trouble of digging a grave.  On two occasions while I was there this hasty burial was followed by the return home of the men, who had been buried alive, to their affrighted relatives.  They had recovered, while in their graves, from prolonged swoons.

In ophthalmia the doctors cup on the temples, and apply to the eyes the pungent smoke of certain roots, the patient, at the same time, taking strong draughts of it up his nostrils.  We found the solution of nitrate of silver, two or three grains to the ounce of rain-water, answer the same end so much more effectually, that every morning numbers of patients crowded round our house for the collyrium.  It is a good preventive of an acute attack when poured into the eyes as soon as the pain begins, and might prove valuable for travelers.  Cupping is performed with the horn of a goat or antelope, having a little hole pierced in the small end.  In some cases a small piece of wax is attached, and a temporary hole made through it to the horn.  When the air is well withdrawn, and kept out by touching