The Relation of Forests in the Atlantic Plain to the Humidity of the Central States and Prairie Region.

MANY of the dreams or presentiments of the early scientists are now coming true every day. The dreams of the alchemists are now almost within the realization of modern chemistry. The gropings of the early biologists are almost within reach of present-day experimental embryology, and so on practically in every science; at first a presentiment, "a hunch," which can not be substantiated by any scientific facts. This, later, with the accumulation of more accurate observations is often entirely denied or minimized, only to reappear again, not as a presentiment any more, but as a scientifically established fact. From the earliest times there existed among laymen, and even scientists, a belief that forests exercised an influence upon the climate of entire countries. With the introduction of accurate methods of meteorological observations, this popular conception has seemingly been greatly discredited. All that most of the meteorologists were willing to admit was that forests have a local influence upon climate, extending only over the territory actually occupied by them. Within recent years, just when this view seemed to be completely disposed of, many new facts came up independently in different countries, which point strongly to the possibility of the forest exerting a potent influence upon the humidity of regions lying far away from it. I shall attempt to consider in the light of these new facts the conditions prevailing in the eastern part of the United States, and to eso n A pr il 15 , 2 01 7