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with wonder and admiration. Bowed down under a sense of his littleness, the man of science thus finds tongues in the trees, which in mute eloquence teach him lessons and impress him with truths more sublime, beautiful, and instructive, than all that were ever conceived in ancient Rome, or uttered by sage in classic Greece.
As we extend the view, we find room for more enlarged and lofty conceptions. Though chemical analysis does not reach back far enough to detect any changes in the components of the atmosphere, we know that there have been changes. Nature has recorded the fact on tablets of the rock, and left evidences of it in the coal fields and other remains which are scattered through the earth. The light and heat from the anthracite fire, which cheers and warms us in a winter's day, came from the sun ages and ages ago, and have been bottled away, as it were, in the earth for man's use, and the present economy of nature and the world. The coal measures of the earth cover many thousand square miles; they, too, are filled by the work of the yellow ray; for it is well known that coal is of vegetable origin. It is almost all carbon. When the trees and plants flourished which produced this coal, the components of the atmosphere were very different from what they now are, for the carbon of this coal was abstracted from the air, Why, then, it may be asked, seeing the quantities of coal that are now consumed, returning its carbon back into the atmosphere, does not the air become tainted, and again unfit for animals constituted as we are? Reasoning by analogy, the answer is plain. Are not the vegetable productions of the earth, and the population of the world, greater now, than they probably have ever been? Under the improvements of agriculture, one acre of ground is now
