dense, and coherent, it would most
likely be a poor amendment on a soil which has much tendency to become
compact, and therefore does not readily free itself from excess of
water.

But even a clay soil, if _thorough-drained and deeply plowed_, may be
wonderfully improved by even a heavy dressing of muck, as then, the
water being let off, the muck can exert no detrimental action; but
operates as effectually to loosen a too heavy soil, as in case of sand,
it makes an over-porous soil compact or retentive. A clay may be made
friable, if well drained, by incorporating with it any substance as
lime, sand, long manure or muck, which interposing between the clayey
particles, prevents their adhering together.

II.--_Noxious ingredients._

a. _Vitriol peat._ Occasionally a peat is met with which is injurious if
applied in the fresh state to crops, from its containing some substance
which exerts a poisonous action on vegetation. The principal detrimental
ingredients that occur in peat, appear to be sulphate of protoxide of
iron,--the same body that is popularly known under the names copperas
and green-vitriol,--and sulphate of alumina, the astringent component of
alum.

I have found these substances ready formed in large quantity in but one
of the peats that I have examined, viz.: that sent me by Mr. Perrin
Scarborough; of Brooklyn, Conn. This peat dissolved in water to the
extent of 15 _per cent._, and the soluble portion, although containing
some organic matter and sulphate of lime, consisted in great part of
green-vitriol.

Portions of this muck, when thrown up to the air, become covered with "a
white crust, having the taste of alum or saltpeter."

The bed containing this peat, though drained, yields but a little poor
bog hay, and the peat itself, even after weathering for a year, when
applied, mixed with one-fifth of stable manure to corn in the hill, gave
no encouraging results, though a fair crop was obtained. It is probable
that the sample analyzed was much richer in salts of iron and alumina,
than the average of the muck.

Green-vitriol in minute doses is not hurtful, but rather beneficial to
vegetation; but in larger quantity it is fatally destructive.

In a salt-marsh mud sent me by the Rev. Wm. Clift, of Stonington, Conn.,
there was found sulphate of iron in considerable quantity.

This noxious substance likewise occurred in small amount in swamp muck
from E. Hoyt, Esq., New Canaan, Conn., and in hardly appr