Page:Popular Science Monthly Volume 36.djvu/589

Rh affecting of all in ancient literature, the fright of the child in Homer's "Parting of Hector and Andromache," the interest, "if we analyze it, belongs rather to an impartial delineation of human life as it is, than to any sympathy with the helplessness and dependence of its earliest stage." While modern art does not show an equal lack of the taste for childhood, it "is comparatively feeble at all times in comparison with the feeling of our own day." This feeling is reflected in its intensity first in the poems of Wordsworth and the pictures of Sir Joshua Reynolds. "This sympathy with childhood," says the writer in the "Spectator" whose essay we have summarized, "which gives its coloring to modern literature and art, is to be traced back to utterances which have influenced more than the literature and art of modern Europe. ’Except ye become as little children, ye can not enter into the kingdom of heaven,' was a saying new to the world. The fresh aspect under which all weakness, all dependence, appeared in the light of that teaching, was evidently bewildering to its hearers." It took centuries for the Christian world to take in the full meaning of that utterance, which has not been realized as a fact of ordinary life till nearly our own time. But now, "for a year or two in this pilgrimage of ours, the most commonplace, the most tiresome of us is invested with this wonderful capacity [of persuasion and conciliation]; every human being has once upon a time hushed enmities and bridged estrangement."

Iron as a Purifier of Water.—The power of iron to remove coloring matter and organic contamination from impure waters has been made capable, by recent improvements in processes, of receiving a greatly extended application. In Prof. Bischof's system, a sand filter which separates the mechanical impurities is underlaid by a mixture of gravel and iron in the proportion of three parts to one. When the water is drawn off from this filter after using, no discoloration is visible in the upper sand, nor till near the iron mixture. In this the particles of gravel and iron become thickly coated and mixed with the reddish, slimy product of the chemical action of the iron; and, still lower down, the mixture is black, and not subject to change. The slimy-coated mixture has to be removed and washed every six months. By another improvement the iron is presented in a state of constant agitation, and the slimy coating being washed away as fast as it is formed, an always clean surface is offered to the water. The working of the method is satisfactory, and may, by adding fresh iron from time to time, be made nearly continuous. The purification depends upon the chemical action of iron on organic matter in solution, and its property of coagulating very finely divided particles of matter so that they can be removed by filtration. The iron, in this process, changes the chemical nature of the organic matter and greatly reduces the albuminoid ammonia; softens the hard scales that form in boilers, and destroys or removes much of the infusorial life in the water.

A Bit of Triassic History.—Mr. W. M. Davis's study of the "Topographic Development of the Triassic Formation of the Connecticut Valley" shows that the country from northwest to southeast suffered from repeated faultings after the trap sheets had taken their places, as extensive surface-flows, in the stratified series, the trend of the faults being to the southwest. The initial constructional regions are represented by the faulted blocks of southern Idaho. A mountainous variety of form prevailed—which may provisionally be called the Jurassic stage of the evolution of the district; but in time—during the Cretaceous—the faulted ridges were reduced to a low, base-leveled plain, in which the present valleys were worn after its elevation. The Connecticut River was originally consequent on the monoclinal faulting; and, while it has entered on a second cycle of life as a result of the elevation of the lowland that was produced in its first cycle, it still persists in the course it first took.

Uranium.—It is now a hundred years since Klaproth (in 1789) discovered the metal which be named after the planet Uranus, then recently discovered by Herschel. Uranic oxide, which is yellow, is used to produce a beautiful golden color, and, with other minerals, opalescent tints in glass and porcelain. The pentoxide is black, and is used in the production of