Page:Popular Science Monthly Volume 1.djvu/680

664 closely investigated almost all the familiar ingredients of animals and vegetables, and, after comparing them, induced the great laws of nutrition and the mutual dependency of the two orders. He found that plants derived their nutriment solely from inorganic substances, taking their carbon from carbonic acid, their nitrogen from ammonia, their hydrogen from water; that animals drew their sustenance from organic substances only; that vegetable albumen had the same composition as the albumen in the egg and the blood, and that its admission was the result of its being dissolved by digestion. He then first announced the theory that the inorganic constituents, the so-called ashes, played an important part in the growth of vegetables, and that without their presence no vegetable structure could subsist. Thousands of facts and results of experiments had previously existed, but no one had found the law. After Liebig's announcement and demonstration, it became the starting-point of a new science.

He has not been spared the struggles which Copernicus and Lavoisier had to encounter; yet it may now be said that the warfare has terminated in his favor. The ships searching for guano-islands on the coast of Peru and in the Pacific Ocean do so upon the advice of Liebig; the agricultural colleges and similar institutions which sprang from his breath, may now be counted by the dozen. He was the first to assert that the most important changes and revolutions in the history of the world arose from the destruction of the wealth of the soil; and that the conquerors of the savage hordes of Central Asia were forced to march on by the violation of a law of Nature. Now, since the change of habitations is an unavoidable, ever-occurring element in the world's history, he who must be considered the greater conqueror is the man who teaches humanity what to do in order not to fall again a prey to Nature's law. Attila and Alaric were driven onward unconsciously, because forced by a natural law; far superior, far more powerful, is the natural philosopher who unfolds the law and teaches how to obey it. More enduring than the supremacy of the Roman Empire is the influence of that knowledge which teaches man how he may live on a soil for an unlimited period of time and with ever-constant result.

All this the illustrious inquirer obtained from the accurate investigations of animal and vegetable bodies; but the results would not have been possible without the improved method of analysis contained in that glass of water.

The causes of great inventions and discoveries have always been small, the results always incalculable—as incalculable as those of the glass of water spilled at Queen Anne's court. The investigator of Nature, therefore, must value every observation, every new fact, for they may result in a glass of water.