Page:Popular Science Monthly Volume 40.djvu/737

Rh to him. In China the population lives almost entirely on vegetables. Opium-smoking slows the processes of digestion, and, in fact, has the same effect as long intestines, and consequently is highly beneficial." Again, the Chinese live in low, undrained grounds, and are consequently liable to attacks of fever and ague. Under similar circumstances the lowlanders of Lincolnshire took to laudanum; the Chinese take opium in another form. Residents in China are struck with the comparative freedom of the people from pulmonary diseases. "That this immunity is not due to chmatic influences is clearly proved by the fact that Europeans and Americans are not more free from the scourge in China than they are in their own countries." Morphia is an anæsthetic, and rarefied as smoke probably an antiseptic. "In this form it would tend to arrest the suppuration of the lungs that takes place in consumption."

Oscillations of Alpine Glaciers.—About thirty years ago, according to Herr von E. Richter, the glaciers of the Alps began a precipitate retreat. In 1870 the ti-aveler often found a stone-strewn plain or an undulating slope of polibhed rock where ten years before he had scrambled over crevassed ice. About five years later, a slight, transitory forward movement was perceptible, while now the indications of an advance are becoming more marked. Similar changes, at earlier dates, are on record, and their history has been studied by Prof. Forel, Ilerr von Richter, and others. The historical period of the oscillations of the glaciers extends back about three centuries, while prior to this the notices are too sparse and vague to be of any real use. In this period eight marked epochs of glacier growth are on record. The first began in 1592, and the last, excluding the slight one of 1875, in 1835. Each was followed by a period of diminution. The intervals between the epochs vary from twenty to forty-seven years. The observations are not numerous enough to give trustworthy indication of a law, but are supposed to hint at one. The changes are connected with climatic variations, but effects are produced more quickly than is generally supposed. In the present century the curves representing the oscillations of the glacier and those of the annual temperature nearly correspond. Some traditions assert that in the middle ages the glaciers had almost melted away from many parts of the Alps, and passes were then crossed by women and children which are now left to experienced mountaineers. Their evidence relates to the cultivation of vines, cereals, etc., in localities where they are no longer grown, and to the former use of passes which are now practically closed. To the former evidence, as Herr Richter shows, little weight can be given. Man and Nature are in constant conflict in the Alps, and the position of the frontier line between their territories is determined by the convenience of the former. If a particular form of cultivation ceases to be remunerative all the advanced posts are abandoned. Herr Richter, likewise, does not give much force to evidence based on the disuse of passes. This is more than likely to have been brought about by the discovery of better ways or the making of new roads. In short, says the Saturday Review, under this author's treatment, "the traditions, not the glaciers, become unsubstantial, and the warm epoch in the mediæval history of the Alps goes the way of many other legends."

Origin of the Colors of Flowers.—Any one, says Mr. E. Williams Hervey, in Garden and Forest, can solve the problem as to the primitive color of flowers by a study of the native wild plants growing by the roadside or in the fields and woods. Two methods, he says, are employed by Nature in the development of colors, one of which he calls the imperfect or foliar development, and the other the normal floral process. In the former, the colors are apparently evolved directly from the green chlorophyl, as the reds, purples, and yellows of autumn leaves; for from some green-colored flowers a rather limited number of dull reds, purples, and yellows are produced. The reds and reddish purples are, however, rare, and appear mostly on the scales of involucres, where they are common, on the spathes of several of the Aracæe, in Salicornia of the salt marshes, which turns red in the fall, and in the castor oil plant of gardens, which turns a reddish purple in all its parts. The author does not find a satisfactory example of yellow evolved