I speak to them and treat them as rational beings, and generally get on well with them in consequence.
I have already remarked on the unhealthiness of Cassange; and Captain Neves, who possesses an observing turn of mind, had noticed that always when the west wind blows much fever immediately follows.

As long as easterly winds prevail, all enjoy good health; but in January, February, March, and April, the winds are variable, and sickness is general.
The unhealthiness of the westerly winds probably results from malaria, appearing to be heavier than common air, and sweeping down into the valley of Cassange from the western plateau, somewhat in the same way as the carbonic acid gas from bean-fields is supposed by colliers to do into coal-pits.

In the west of Scotland strong objections are made by that body of men to farmers planting beans in their vicinity, from the belief that they render the mines unhealthy.

The gravitation of the malaria from the more elevated land of Tala Mungongo toward Cassange is the only way the unhealthiness of this spot on the prevalence of the westerly winds can be accounted for.

The banks of the Quango, though much more marshy, and covered with ranker vegetation, are comparatively healthy; but thither the westerly wind does not seem to convey the noxious agent.
FEB.20TH.On the day of starting from Cassange, the westerly wind blew strongly, and on the day following we were brought to a stand by several of our party being laid up with fever.