confirmatory of sacred history does remain, I pray to be guided
thereunto. If the sacred chronology would thereby be confirmed, I would
not grudge the toil and hardships, hunger and pain, I have endured--the
irritable ulcers would only be discipline.

Above the fine yellow clay schist of Manyuema the banks of Tanganyika
reveal 50 feet of shingle mixed with red earth; above this at some parts
great boulders lie; after this 60 feet of fine clay schist, then 5
strata of gravel underneath, with a foot stratum of schist between them.
The first seam of gravel is about 2 feet, the second 4 feet, and the
lowest of all about 30 feet thick. The fine schist was formed in still
water, but the shingle must have been produced in stormy troubled seas
if not carried hither and thither by ice and at different epochs.

This Manyuema country is unhealthy, not so much from fever as from
debility of the whole system, induced by damp, cold, and indigestion:
this general weakness is ascribed by some to maize being the common
food, it shows itself in weakness of bowels and choleraic purging. This
may be owing to bad water, of which there is no scarcity, but it is so
impregnated with dead vegetable matter as to have the colour of tea.
Irritable ulcers fasten on any part abraded by accident, and it seems to
be a spreading fungus, for the matter settling on any part near becomes
a fresh centre of propagation. The vicinity of the ulcer is very tender,
and it eats in frightfully if not allowed rest. Many slaves die of it,
and its periodical discharges of bloody ichor makes me suspect it to be
a development of fever. I have found lunar caustic useful: a plaister of
wax, and a little finely-ground sulphate of copper is used by the Arabs,
and so is cocoa-nut oil and butter. These ulcers are excessively
intractable, there is no healing them before they eat into the bone,
especially on the shins.