THE April issue of the "Journal of the Royal Colonial Institute" contains a full report of Dr. Patrick Manson's recent paper headed "A School of Tropical Medicine," of which a considerable portion is devoted to the theory of the propagation of malaria by the mosquito. Of all tropical diseases, many of which in summer embrace Shanghai in their territory, malaria is the chief. "It is the great disease of the tropics. It is the principal cause of sickness and death there, and of social stagnation. It is the King there, and like some brutal tyrant, it blasts its subjects and its Kingdom. It, and practically it alone, is the reason why Africa is the Dark Continent; why some, in fact most, of the fairest and most fertile regions of the earth are but howling wildernesses covered with worthless jungle and inhabited only by wild beasts and a sprinkling of wilder men. Five millions die annually of fever, principally malarial, in British India alone. Over one third of our soldiers there, European and native, suffer annually from malaria. Apply this proportion to the whole civil population, and we from climate. This is a common and most misleading fallacy. Di ease may be influenced by, but it cannot be caused by climate. Disease is caused by beasts and plants, and we have dominion over these. To compete successfully with beasts and plants all we require is knowledge and the skill, the will, and the opportunity to apply it. We can cut down the mightiest oak, and we can draw forth leviathan with a hook. If we can do this, surely we can subdue the feeble bacterial and the feeble protozoal germs of disease."
The germ of malaria lives in the human blood, and, once introduced, will live and multiply for an indefinite period in any country or \climate. But it can only be trans-j mitted to another human being by means of a mosquito, and fortunately there are only certain varieties of the mosquito that are effective transmitters of the malarial germ, and {only such individual members of those particular varieties as have previously fed on human blood which lat the time contained malarial parasites. Those who object that there used to be plenty of mala lin England in the fen country but with a flat contradiction. He say: 0 mosquitoes Dr. Manson meets
There are plenty of mosquitoes in England, at least seven kinds, only in England they are called ' gnats.'" Malaria has been nearly driven out of England by the- drainage which has destroyed the stagnant pools which are the breeding-places of the mosquito, and by the cheapening and wide use of quinine which, as we showed some time ago, kills the germ of malaria as surely as arsenic kills the rat.
Text read from the printed page and cleaned; old type leaves the occasional error.