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titles, although Baron Liebig seems to almost ignore the benefits of any 
but inorganic manures. 
Manures are generally divided into two classes, and whether this divi¬ 
sion has any foundation in nature or not, I shall adopt it as being an 
easy and simple classification : 
1st. Organic manures, which of course must contain all the elements 
of the former organization. 
2d. Inorganic manures, mineral manures, stimulants either saline or 
alkaline. 
This division is entirely arbitrary, as is the term stimulants, as though 
mineral manures were any thing different in action from vegetable, or 
possessed a stimulating power which the latter does not equally possess. 
The term stimulant as applied to mineral fertilizers is entirely misapplied; 
for, as we have before defined, the action of manures is not any stimu¬ 
lation of the plant to greater activity in performing its natural functions, 
but simply giving it the means of performing them the more rapidly. 
Any agent which tends to restore, when weakened by cropping—to 
create, when deficient by nature—or to augment the fertility of the soil, 
is termed a manure. Organic manures, from their complex nature, are 
better fitted for general and indiscriminate use than those of simpler com¬ 
position, and are in consequence in more general use ; and here, as else¬ 
where, practice preceding theory, has declared them the most important. 
Any manure to be efficacious must possess this complex nature; and this 
principle becomes of great importance when we consider how many 
farmers have been misled by the notices of the astonishing effects of some 
mineral manure, as heralded in the Agricultural Journals, and being in¬ 
duced to follow their example have met with complete failure. Lime 
spread upon barren sand would not insure a plentiful crop of wheat; nor 
plaster, however plentifully sown, upon sterile soil, produce an abundant 
yield of grass. Other elements must pre-exist in the soil, or be furnished 
by the husbandman. 
Therefore considering organic manures to be of greater importance* 
•we will first consider them ; and the first question that naturally arises 
is —On what does the efficacy of manures depend? In the solution of this 
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