664. THE POPULAR SCIENCE MONTHLY. 



closely investigated almost all the familiar ingredients of animals and 

 vegetables, and, after comparing them, induced the great laws of nutri- 

 tion 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 hydro- 

 gen from water ; that animals drew their sustenance from organic sub- 

 stances only ; that vegetable albumen had the same composition as the 

 albumen in the egg and the blood, and that its admission was the re- 

 sult 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 Lavoi- 

 sier 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 influ- 

 ence 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 inves- 

 tigations 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 Na- 

 ture, therefore, must value every observation, every new fact, for they 

 may result in a glass of water. 



