8 MASSACHUSETTS AGRICULTURE. 



to be piled up in the courtyard and set on fire ; because, said 

 he, " In all these books, I find no principles ; they can, there- 

 fore, be of no use to any man." What the law of gravitation 

 is in astronomy, what steam is in mechanics, what the Constitu- 

 tion of the United States is in government, the beginnings of 

 epochs, such is the newly developed science of chemistry, in 

 agriculture. That light and heat from the sun, that water, 

 air and earth were necessary to vegetation, was understood. 

 Experience had shown that certain crops were better adapted to 

 some soils than to others ; that a sviccession of different crops 

 was better than a succession of the same crops ; that fallows 

 increased the vegetative power of the land. These, and such as 

 these empirical rules, were known and obeyed ; and yet, in 

 spite of husbandry of this sort, crops would in time deteriorate, 

 and the soil lose its virtues beyond the skill of the farmer to 

 devise the means of restoration. The writings of Columella 

 and Varro, while they disclose a system of Roman husbandry, 

 most careful, methodical and painstaking, at the same time 

 reveal the appalling, irremediable fact, that the production per 

 acre had largely diminished. Pilled with the ancient faith that 

 the golden age of the race was in its prime, and that then the 

 arts were divinely established' in their perfection, the Roman 

 farmers dreamed that a declining agriculture was due to some 

 lost charm, some missing precept, which tradition had failed to 

 transmit down the course of the centuries from hero-ancestors 

 taught by the gods. Modern agriculture has exhibited the 

 same stages of decadence. But modern science has revealed 

 the causes of such decline and placed within the control of 

 man the powers that will eiiable him to resist this downward 

 tendency, if he will but use them. Earth, air and water have 

 been resolved into their priomordial elements. A searching 

 analysis has shown what essentials of its life and substance the 

 plant draws from the soil, and what from the atmosphere. The 

 microscope has revealed the complex physiology through which 

 by a subtle alchemy the sun in the heavens converts the mineral 

 earth, and air and water, into an organic growth that is food for 

 the nations. Among the most valuable generalizations of science 

 is the demonstrated truth that certain known constituents of 

 the soil do in the process of vegetable growth, enter into the 

 essential constitution of the plant, and as a consequence, that 



