A PRIZE ESSAY. 
27 
acids of the salts of dung act, turn to tne bases or the 
alkalies and metals and earths of these salts. What 
is their action ? What purpose do they serve in dung 
applied as manure ? First, they enter into and form 
a part of the living plant, they form a part of its 
necessary food, as much as do the constituents of 
mould. Secondly, when these alkalies and metallic 
bases are let loose, by the disuniting power of a 
growing plant, then they act as alkalies upon mould. 
They hasten decay, render mould more soluble, fit it 
to become food for plants. This account of the action 
of mould and salts in cattle dung may appear to you, 
reader, long and hard to be understood. I do request 
you not to pass it over on that account. A patient 
reading, perhaps some may require two or more read¬ 
ings, will put you in possession of all you need know, 
to understand the why and the wherefore of the action 
of mould and salts of whatever manure may be used. 
What has been said of the action of mould and salts 
in cattle dung, is equally applicable to all manures. 
If, then, you bend your bones to this subject, and 
master it, your labor of understanding the action of 
other manures will be reduced to the mere statement 
of the several substances which they may contain. 
We therefore proceed to point out other manures, 
composed of the droppings of animals. 
SECTION VI. 
OF NIG-HT SOIL, HOG MANURE, HORSE AND SHEEP DUNG-. 
These have not all been analyzed with the same 
degree of care and as often as has cattle dung; some, 
as, for instance, night soil, have been examined thor¬ 
oughly but once. Now it is not quite fair to base 
our reasoning upon these single analyses, and say that 
