Directory_and_Chronicle_1850 — Page 366

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ART. V

Showers of Sand.

JUNE,

Remarks on showers of sand in the Chinese Plain. By D. J. MACGOWAN, M. D.

THE phenomenon of falling sand is occasionally observed through a great extent, if not the entire portion, of the vast Plain of China. It is of such frequent occurrence that the Chinese regard it with no more surprise than they do the flitting meteor. Probably no year passes without several of these showers, though frequently so minute as to escape general observation. Perhaps as often as once in three years they are very heavy, but it is seldom that sand falls in such a large quantity as during the last shower. The phenomenon was wit- nessed three times during the present year, within a period of five weeks; the last and greatest commenced on the 26th of March, and continued four days without intermission, varying however in intensi- ty. The wind blew from the north, northeast, and northwest, frequent- ly shifting between these points, and varying in strength from a perfect calm to a brisk breeze. The altitude of the barometer was from 29.40, to 30.00 (rather lower than before and after the shower). The thermometer ranged from 36° to 81° F. No rain had fallen for six weeks, and the hygrometric state of the atmosphere was very high. Neither cloud, fog, nor mist obscured the heavens, yet the sun and moon were scarcely visible, the orb of day appeared as if viewed through a smoked glass, the whole sky presenting a uniform rusty hue. At times this sameness was disturbed, exhibiting between the spectator and the sun the appearance of a water-spout, owing to the gyratory motions of the impalpable mineral. The sand penetrated the most secluded apartments; furniture wiped in the morning would be so covered with it in the afternoon, that one could write on it legibly. In the streets it was annoying, entering the eyes, nostrils and mouth, and grating under the teeth. My ophthalmic patients generally suffered a relapse, and an unusual number of new cases soon after presented. Were such heavy sand storms of frequent occurrence, diseases of the visual organs would prevail to a destructive extent. The effect was the same when observed from the Niugpo Tower, and from the summit of the low mountains in the neighborhood of the city.

The specimens I gathered fell on a newspaper placed on the roof of a house. The whole quantity which fell was about ten grains to the square foot. It should be remarked, however, that during the four days the dust seemed suspended in the air for several hours at a time, scarcely an appreciable quantity falling during these intervals. The Chinese call it yellow sand; it is an impalpable powder of that