tures, till they become accustomed to it; but these trials sometimes cost them their lives. The urine of an Hottentot thus prepared is esteemed an excellent antidote, or counterpoison, and is therefore drank by such as have been bitten by serpents."
If the former part of this account could be relied on, it should seem that these savages were acquainted with a method of producing by inoculation of animal poison a milder disease, which, like the vaccine, rendered the system proof against a more formidable virus. There is a curious passage in the adventures of Robert Drury, which bears, though distantly, upon this subject. An insect like a cow-tick, called poropongee, is found in that part of Madagascar which the Virzimbers possess, and in no other part of the country. Its bite is said to occasion an illness which lasts six or eight weeks, but to which no person is subject a second time, and the
