Page:Popular Science Monthly Volume 36.djvu/694

676 moment. One feels that the destiny of man is assuredly noble.

The student will not go far in his quest before facts begin to accumulate which are fraught with the deepest significance. He has known perfectly well all along that only a certain amount of heat can be obtained from burning a definite quantity of coal, and that it will be given out in proportion to the rapidity with which the burning is accomplished. If he wishes his room to be warmer, he opens the draught and gives a more abundant supply of air to the fire. The operation has been too often repeated to excite any wonder. But it becomes significant when he discovers that all other chemical reactions rest upon precisely the same principle. Each substance is found to have a definite combining power, and in every reaction, however simple or complex it may be, a definite quantity of one element unites with a definite quantity of another. If too much of either element be taken, it will be left over. But this is the law of definite proportions discovered by Dr. Dalton in the early part of the century and now the very corner-stone of chemical science. If the student further inquire what has become of the coal and the oxygen whose union we call combustion, he will find that a colorless gas, carbonic-acid gas, has been formed whose weight is exactly equal to the sum of their weights. Other illustrations will yield parallel results, and the far-reaching conclusion will be forced upon him that man is neither able to create matter nor to destroy it. This single truth once really apprehended gives a stability to thought which can scarcely come from any other single consideration. The universe is seen to be in an eternal ebb and flow, but its materials are seen to be constant. Once persuaded of the fact, and the suspicion arises that the same may be the case with heat and other forms of motion. And such he finds to be the truth. He learns that energy likewise is neither creatable nor destructible, and that all the work going on in the universe is simply that of transformation. New distributions of motion and new combinations in matter, these make up the cosmic life, but the sum total in each case remains unaltered. Perpetual motion is seen to be more than a possibility; it is found to be a necessity. One sees all of the universe in a state of ceaseless flux, sees that nothing stands still, that growth involves never-ending change, and becomes prepared to accept without fear those changes of opinion which intellectual growth necessitates as well as that great change of state which we call death. I can not hold as idle or of secondary import the speculations which these considerations engender. It is good for a man to penetrate as far as he may into the established order of the universe, for its secret is his secret, its process is his process. Curious thoughts spring from brooding over these doctrines of the conservation of force