4^2 THE POPULAR SCIENCE MONTHLY. 



ceed some day in finding a way of regulating the seasons ; some 

 Americans already profess to be able to produce rain at will by 

 means of dynamite. But their hypotheses, resuscitated from the 

 notions of the Romans concerning the influence of great battles 

 on the atmosphere, do not seem to have as yet been confirmed by 

 experiment. But, on the other hand, the innovations that were 

 criticised so sharply by the English humorist are in our days be- 

 coming the bases of field labors. 



Scientific agriculture is gradually becoming more fully substi- 

 tuted for the agriculture of tradition, and it is adding in an un- 

 anticipated degree to the wealth of nations. 



To the progress of this art, which is more manifest every day, 

 our society has never ceased to lend the most active aid, both 

 through the individual labors of its members and by prizes and 

 incentives offered by it to inventors. It has zealously given its 

 assistance to all the great innovations foreseen in the last century 

 by some advanced minds, which the literary critics of the time 

 turned into derision, but which have been especially developed 

 during the past fifty years. 



The advance of material science has, in fact, served as the basis 

 of this surprising metamorphosis of agricultural practices which 

 we witness and admire; and the mental and moral advance of 

 the human mind has likewise transformed under our very eyes 

 the education of the peasant, now raised to the dignity of a citi- 

 zen. Every day he is gaining a closer acquaintance with science ; 

 he is learning to take advantage of its teachings for the increase 

 of his production and for the amelioration of the conditions of his 

 formerly so miserable existence. Three sciences in particular 

 have contributed to this evolution of agriculture — mechanics, 

 chemistry, and physiology. The endlessly various agricultural 

 machines permit us to sow, till, and harvest over large surfaces, 

 and with a small expenditure of human manipulation. The pro- 

 ductive force of Nature has thereby been wonderfully increased. 



But the machines of themselves create nothing ; they are only 

 applied to products already elaborated under the operation of 

 natural forces. The processes which preside at this elaboration, 

 the manner in which the plants are fed at the expense of the air, 

 water, and soil, to serve afterward as food for animals, have long 

 been mysteries. It has hardly been a century since they began to 

 be revealed to us by chemistry, which they could not have been 

 earlier, so long as we were not acquainted with the real chemical 

 elements common to plants and animals, and had not discovered 

 the secret of their passage through living organisms. Chemistry 

 exposed this secret when it disclosed the existence of the elements 

 themselves ; it has taught us to recognize them and to measure 

 their proportions in plants and animals ; it has established, first, 



