under the
term of horse-sickness (peripneumonia) exists in such virulence over
nearly seven degrees of latitude that no precaution would be sufficient
to save these animals. The horse is so liable to this disease, that only
by great care in stabling can he be kept any where between 20 Deg.
and 27 Deg. S. during the time between December and April. The winter,
beginning in the latter month, is the only period in which Englishmen
can hunt on horseback, and they are in danger of losing all their studs
some months before December. To this disease the horse is especially
exposed, and it is almost always fatal. One attack, however, seems to
secure immunity from a second. Cattle, too, are subject to it, but only
at intervals of a few, sometimes many years; but it never makes a clean
sweep of the whole cattle of a village, as it would do of a troop of
fifty horses. This barrier, then, seems to explain the absence of the
horse among the Hottentots, though it is not opposed to the southern
migration of cattle, sheep, and goats.

When the flesh of animals that have died of this disease is eaten, it
causes a malignant carbuncle, which, when it appears over any important
organ, proves rapidly fatal. It is more especially dangerous over the
pit of the stomach. The effects of the poison have been experienced
by missionaries who had eaten properly cooked food, the flesh of sheep
really but not visibly affected by the disease. The virus in the flesh
of the animal is destroyed neither by boiling nor roasting. This fact,
of which we have had innumerable examples, shows the superiority of
experiments on a large scale to those of acute and able physiologists
and chemists in the laboratory, for a well known physician of Paris,
after careful investigation, considered that the virus in such cases was
completely neutralized by boiling.

This disease attacks wild animals too. During our residence at Chonuan
great numbers of tolos, or koodoos, were attracted to the gardens of the
Bakwains, abandoned at the usual period of harvest because there was no
prospect of the corn ('Holcus sorghum') bearing that year. The koodoo is
remarkably fond of the green stalks of this kind of millet. Free feeding
produced that state of fatness favorable for the development of this
disease, and no fewer than twenty-five died on the hill opposite our
house. Great numbers of gnus and zebras perished from the same cause,
but the mortality produced no sensible diminutio