PRESENT THEORY AND PRACTICE OF MINERAL MANURES. 429 
abandoned. “Tull and Buel believed in deep cultivation, as enabling the 
soil to produce larger crops by supplying food more abundantly to the 
crops, and so it did; but it was costly and advanced the price of food, 
and after a while the ground would bear no more deep cultivation, not 
yielding an increased return commensurate with the increased labor. 
Von Thaer in Germany and Boussingault in France were the ablest 
supporters of the view that organic matter (chiefly vegetable matter 
decaying) is the great pabulum of plants, and, if this is in sufficient 
amount in the soil, crops will grow luxurianily. But even with abund- 
ant supplies of humus, as this vegetable matter is called, in the soil the 
ground deteriorated, less weight of roots and grain was raised, and the 
land became exhausted, or sick of the crops, as it is sometimes said. 
Then followed the belief that farm manure, the excrement of cattle and 
horses and the waste of fields, is the true fertilizer, and that if it is ap- 
plied to the soil in sufficient quantity all crops will grow and produce 
abundantly. This belief now holds firm possession of the minds of the 
agriculturists of Great Britain and the United States, and the agri- 
cultural logic in a circle, heard in the after-dinner speech at the Farm- 
ers’ Club, expresses it forcibly:—The more manure the more reots, the 
more roots the more cattle, the more cattle the more manure, and the 
more manure the more roots, and soon. Itis very difficult to make the ag- 
riculturist see the error in this argument, or to convince him that every- 
thing that passes through the body of a four-footed animal is not manure 
or food for plants. Nothing of late years has more fully demonstrated 
the fallacy of depending upon farm manure as the only and sufficient fer- 
tilizer for farm crops of all kinds, than the experiments of Georges Ville, 
carried on near Paris during the past ten years, and, although but little 
has been heard of them outside of that country, they have taken a deep 
hold on the public mind in rural France, and therefore deserve to be 
brought fully before the farmers of this country. While Liebig has 
demonstrated that barn-yard manure is the most complete of all natural 
manures, as they may be called, he has also shown us that it does not suf- 
tice to restore to the earth all the substances which have been abstracted 
from it, because the manure is made only from the straw and the resi- 
duum of the food consumed by cattle, while a large portion of the grain, 
the live cattle, and the wool of the flock, is sold off in the market, and 
returns nothing to the soil. TFarm-yard manure, therefore, will not 
wholly suffice as a fertilizer, and the necessity for complementary ma- 
nures arises; that is, the use of chemical substances which shall supply 
those mineral elements which have been abstracted, and are not in the 
barn-yard manure. Perhaps too much reliance has been placed upon the 
use of farm manure alone as the only fertilizer necessary. It is dif- 
ficult to make American farmers think otherwise, and if the experiments 
and results given here should shake their faith and sole dependence on it, 
some benefit may accrue from this presentation of the subject. Liebig 
uses the following strong language in reference to the experimental 
farm at Hohenheim: 
The history of the farming at Hohenheim is particularly worthy of attention. Up 
to 1064 the directors placed at the head of the establishment were what people called 
practical men; thatis to say, the management of the farm was intrusted to agricultur- 
ists, who knew how to work the soil with profit, meaning by this word profit the 
amount of money got out of the earth, without reference to the condition in which the 
earth has been put by this so-called profitable farming * * * At Hohenheim 
complete accounts are kept of the yearly yield, and the results of successive years give 
no uncertain reflex of the condition to which the soil is reduced. Aecording to the 
rules adopted in the management of this farm, it was necessary that the conditions of 
fertility should be found perpetually in the soil, which should have been inexhaustible. 
According to these principles, success should solely depend upon the skill and dexterity 
