"These paludian fevers, which are prevalent more especially during the rainy season, attack more particularly the rubber collectors--an ignorant and primitive population who know nothing of the most elementary rules of hygiene. Careless or imprudent whites pay the same penalty. "The lack of medical attendance, intemperance, negligence which results in the drinking of stagnant water drawn from pools or swamps or from the river banks; above all, the bites of the mosquito, against which no protection is employed, and which convey malaria to healthy but debilitated persons: these are the causes of the ravages occasioned by paludism in this region, as throughout the Amazon basin. "These conditions do not obtain throughout the Territory; there are numerous healthy localities as, for example, along the middle reaches of the Madre de Dios, in all parts which lie at any altitude, and in regions not subject to floods where a portion of the forest has been cleared in order to give the beneficent breezes a free course. On the other hand, and we speak from long personal experience, any healthy individual of robust or even average constitution can maintain himself in good health, suffering, in the long run, from nothing worse than a little anæmia, by observing the following rules: "Do not drink stagnant water unless it has been boiled; if one must drink unboiled water take it from the river, not from the bank, but from the middle of the current; do not walk or ride or exert yourself in the morning fasting; cover the loins with a belt of wool or flannel; take short but frequent baths or douches in order to facilitate perspiration and to avoid congestion of the pores; and in fever belts, or during the rainy season, take daily, as a preventive, four to eight grains of sulphate or hydrochlorate of quinine (in a cachet or compressed in tabloids) as well as a few granules of arsenic; finally, keep to an abundant and nourishing diet and do not forget that the nights being cool it is indispensable to take warm clothing and good blankets; and, most important of all, never omit the protection of mosquito-nets. "Such is the territory of Colonias and the greater portion of El Beni, a land of magnificent vegetation; it is regarded, not without reason, as a country where tropical agriculture may have a future before it. At present this vast country possesses a population of only some 40,000 to 45,000 inhabitants, without counting its 15,000 to 18,000 wild Indians, a population of which the greater portion if not the whole is occupied in the production and transport of rubber, the chief product of the territory and the neighbouring countries."[20] * * * * *