Page:Popular Science Monthly Volume 38.djvu/843

Rh —Natives of the tropics, and more especially negroes, whether at home or abroad, are peculiarly subject to this acute fever. The death-rate and average of severe cases are among them exceptionally high.

is also remarkably rapid and frequent with these races when sojourning for many months in cold climates, but less so with the southern Asiatic.—The Practitioner.



HE following pages record impressions and observations made in the spring of 1889, during a brief sojourn in the Nile Valley, and a more deliberate study of the Sinaitic Peninsula. In discussing one's experience on a journey the weather claims early notice. In February, at the hotel in Cairo, the thermometer ranged from 60° at 8 to 78° at 3 ; but on the Nile steamer much greater extremes were noted, 54° at midnight (February 19th) to 87° at 2.30 p. M. (February 9th). In the shade the heat was rarely oppressive.

The temperature in the desert in March was favorable to the traveler's comfort, with rare exceptions; the thermometer ranged from about 60° to 80° in twenty-four hours at the sea-level, and from 48° to 75° at the elevation of about five thousand feet.

The highest evening temperature was on March 17th, after the khamsin had blown all day—at 7, 84°. The lowest temperature observed was on March 20th, in camp about three thousand feet above the sea—at 6.30, 33°. (In February, 1874, Rohlf noted in the Libyan Desert a minimum temperature of 23°.) In considering the physiological effects of these temperatures one must remember the extreme dryness of the atmosphere in the desert.

My first experience in Egypt was calculated to give the impression that it is a rainy country, for I saw two showers in three days. In passing through the Suez Canal (January 31st), a heavy shower, lasting half an hour, drove the passengers to shelter, and a brilliant rainbow delighted beholders. Two days later, rain again fell at night in Cairo, making the dirty streets more nasty still. Of course this experience was exceptional, as rain is a rarity in Cairo. Authorities give the rainfall at Alexandria as about eight inches per annum, and at Cairo about