e power of _peat_, in general, to absorb ammonia, if we
reckon them on the organic matter alone. Calculated in this way, the
organic matter of the Beaver Pond peat (which constitutes but 68 _per
cent._ of the dry peat) absorbs 1.4 _per cent._ of free ammonia, and 1.9
_per cent._ of ammonia out of the carbonate of ammonia.

Similar experiments, by Anderson, on a Scotch peat, showed it to
possess, when wet, an absorptive power of 2 _per cent._, and, after
drying in the air, it still retained 1.5 _per cent._--[Trans. Highland
and Ag'l Soc'y.]

When we consider how small an ingredient of most manures nitrogen is,
viz.: from one-half to three-quarters of one _per cent._ in case of
stable manure, and how little of it, in the shape of guano for instance,
is usually applied to crops--not more than 40 to 60 lbs. to the acre,
(the usual dressings with guano are from 250 to 400 lbs. per acre, and
nitrogen averages but 15 _per cent._ of the guano), we at once perceive
that an absorptive power of one or even one-half _per cent._ is greatly
more than adequate for every agricultural purpose.

III.--_Peat promotes the disintegration of the soil._

The soil is a storehouse of food for crops; the stores it contains are,
however, only partly available for immediate use. In fact, by far the
larger share is locked up, as it were, in insoluble combinations, and
only by a slow and gradual change can it become accessible to the plant.
This change is largely brought about by the united action of _water_ and
_carbonic acid gas_. Nearly all the rocks and minerals out of which
fertile soils are formed,--which therefore contain those inorganic
matters that are essential to vegetable growth,--though very slowly
acted on by pure water, are decomposed and dissolved to a much greater
extent by water, charged with carbonic acid gas.

It is by these solvents that the formation of soil from broken rocks is
to a great extent due. Clay is invariably a result of their direct
action upon rocks. The efficiency of the soil depends greatly upon their
chemical influence.

_The only abundant source of carbonic acid in the soil, is decaying
vegetable matter._

Hungry, leachy soils, from their deficiency of vegetable matter and of
moisture, do not adequately yield their own native resources to the
support of crops, because the conditions for converting their fixed into
floating capital are wanting. Such soils dressed with peat or green
manured, at once acqui