quitoes are engendered by frost and exterminated by sunshine?
Yet, if his attention had been chiefly devoted to the comparative study of mosquito ointments and mosquito bars, he might, for the rest, have been misled by such circumstances as the fact that gnats abound near the icy shores of Hudson Bay and are rarely seen on the sunny prairies of Southern Texas.
In all the civilized countries of the colder latitudes, catarrhs are frequent in winter and early spring, and less frequent in midsummer: hence, the inference that catarrhs are caused by cold weather and can be cured by warm air.
Yet of the two fallacies, the mosquito theory would, on the whole, be the less preposterous mistake, for it is true that long droughts, by parching out the swamps, may sometimes reduce the mosquito plague; but no kind of warm weather will mitigate a catarrh, while the patient persists in doing what thousands never cease to do the year round, namely, to expose their lungs, night after night, to the vitiated, sickening atmosphere of an unventilated bedroom. "Colds" are, indeed, less frequent in midwinter than at the beginning of spring. Frost is such a powerful dis-
