Page:Popular Science Monthly Volume 24.djvu/255

Rh that follows; or, on the other hand, of a fatalist doctrine of vegetable spores or organisms of the lowest grade making ceaseless war upon mankind. The world has a way of finding out the truth by its experiences on the large scale. It settled the inane theoretical objections to the value of cinchona-bark, and it will probably form its own opinion on the relative merits of the vegetable-spore theory of malaria and the theory of exposure and climatic vicissitudes. It will be a regrettable circumstance if in this matter the profession has to follow public opinion instead of leading it.



CIENTISTS as well as economists and statesmen are turning with a scrutiny, renewed as each year advances, toward the great region of middle Asia—a territory which, if it supplies society with immigrants much too thrifty for the tastes of our broader-minded Celtic brethren, bids fair in many ways to furnish materials for scientific research that can be compared in interest to no other portion of the world's surface. Without delaying to mention here the recent travelers who are rapidly lessening the bounds of that tract, still confessed to be the least known area of the globe, it is our purpose to direct attention to a geological phenomenon among the most important as well as peculiar of any hitherto brought to light in this field of investigation: we mean the loess-beds covering a great portion of Northern China.

The term loess, now generally accepted, has been used to designate a tertiary deposit appearing in the Rhine Valley, along the Danube, and in several isolated sections of Europe. Its formation has heretofore been ascribed to glaciers, but its enormous extent and thickness in China demand some other origin. The substance is a brownish-colored earth, extremely porous, and, when dry, easily powdered between the fingers, when it becomes an impalpable dust that may be rubbed into the pores of the skin. Its particles are somewhat angular in shape, the lumps varying from the size of a peanut to a foot in length, whose appearance warrants the peculiarly appropriate Chinese name meaning "ginger-stones." After washing, the stuff is readily disintegrated, and spread far and wide by rivers during their times of flood. Mr. Kingsmill, in the "Journal of the Geological Society" (London), states that a number of specimens, which crumbled in the moist air of a Shanghai summer, rearranged themselves afterward in the bottom of a drawer in which they had been placed. Every atom of loess is perforated by small tubes, usually very minute, circulating after the manner of 