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of the soil was given much consideration, and then, as now, 
different theories were put forth. Aristotle believed that matter 
could be divided into the four elements of air, earth, fire and 
water. About the beginning of the seventeenth century Van 
Helmont believed he had proved that all of the products of 
vegetables were capable of being generated from water. Two 
undred years ago rane Full put forth the theory that the 
food of plants consisted of fine particles of soil — in ath 
minute form were taken up and absorbed by p 
his theory was a mistaken one, his practice of fine eee pe 
to the best methods of today. He planted wheat in rows and 
cultivated it while it was growing the same as corn. To meet 
with the highest degree of success and satisfaction in the owner- 
ship and management of land it is now necessary to know much 
about the soil. That which may be considered poor or infertile 
«soil may be capable of the largest production. It may contain 
deleterious compounds in the form of certain acids that make 
the food substances of plants unavailable. 
Not many years ago there was not a single soil compound that 
had been separated and identified. Now there are over thirty- 
six, some of which are antagonistic to the life of some of our most 
valuable plants. In this fact may be found one cause of many 
‘of the diseases of race ee an environment that is destruc- 
tive to the health of pla: 
Medical science ae ee that proper sanitation is 
‘essential to the health and life of human beings and to all animal 
life, and agricultural chemistry in its modern study and research 
as made a like discovery, that plants give off from their bodies 
excreta the same as is done by animals that will produce an 
environment which in time will be destructive to their own life, 
but which, however, may be beneficial to other plants. When 
dairy cattle are long kept confined in stables, where their excreta 
is allowed to produce unsanitary conditions, and pure air is not 
provided by proper ventilation, they soon contract disease. 
Bovine tuberculosis is often caused by unsanitary conditions, 
and environment surrounding cattle, yet the fermenting excreta 
that will cause the disease and death of cattle will give life and 
