94 THE CULTURE. OF FARM CROPS. 



<?ally with the species. Moreover it was found that when a 

 plant was grown out of the soil ; and with its roots envel- 

 oped only in water; it grew with equal luxuriance as if 

 grown in the soil, provided that the water held in solution 

 the same mineral substances which were found in the ash of 

 the same species, together with the needed quantity and 

 variety of its organic elements. Thus the soil was found to 

 possess functions of more importance to plant growth than 

 the mere mechanical support for its roots, and really sup- 

 plied to the plant a number of constituents without which, 

 or any one of which, the growth was enfeebled or wholly 

 failed. Hence there w r as no longer any doubt that the ash 

 of plants represented really essential portions of their nutri- 

 ment, and the farmer then was able to understand the whole 

 secret of the art of manuring ; viz ; that to grow abundant 

 crops every constituent part of the plants must be present 

 in the soil, or if not, they must be supplied to it in the form 

 of manures or fertilizers. This discovery necessarily modi- 

 fied the notions held by farmers, and regulated the prac- 

 tices of agriculture in every branch. One of the most use- 

 ful reforms in thought and practice was to abolish the idea 

 which was prevalent among unintelligent farmers, viz, that 

 books and other literature were totally useless to them, and 

 that the only way to become good farmers was to spend a 

 life time in copying the ways and methods of older men, 

 and learning from them what they knew of their art. We 

 have now learned that while this is all useful, there is some- 

 thing else which is pre-eminently necessary ; viz ; to study 

 the laws of plant growth and with the knowledge thus 

 gained from books and other sources to give careful and in- 

 telligent consideration to the nature of the soil ; the princi- 

 ples upon which its proper culture are based ; the most 

 perfect machinery for this culture; the ait ot manuring; 

 the nature and use of artificial fertilizers; and the produc- 

 tion of manure, made richer in the needed elements of 

 pla.nt growth by feeding cattle. And for the purpose of 

 encouraging this study and of spieading abroad the neces- 

 sary information for it ; a special literature devoted to agri- 



