e investigations of
Boussingault and Knop, while the explanation of it is furnished by the
researches of Schoenbein and Zabelin. To attempt any elucidation of it
here would require more space than is at our disposal.

It is plain from the contents of this paragraph that peat or swamp muck
is, in general, an abundant source of nitrogen, and is often therefore
an extremely cheap means of replacing the most rare and costly
fertilizers.

II.--With regard to the _inorganic matters of peat_ considered as food
to plants, it is obvious, that, leaving out of the account for the
present, some exceptional cases, they are useful as far as they go.

In the ashes of peats, we almost always find small quantities of
sulphate of lime, magnesia and phosphoric acid. Potash and soda too, are
often present, though rarely to any considerable amount. Carbonate and
sulphate of lime are large ingredients of the ashes of about one-half,
of the thirty-three peats and swamp mucks I have examined. The ashes of
the other half are largely mixed with sand and soil, but in most cases
also contain considerable sulphate of lime, and often carbonates of
lime and magnesia.

In one swamp-muck, from Milford, Conn., there was found but two _per
cent._ of ash, at least one-half of which was sand, and the remainder
sulphate of lime, (gypsum.) In other samples 20, 30, 50 and even 60 _per
cent._ remained after burning off the organic matter. In these cases the
ash is chiefly sand. The amount of ash found in those peats which were
most free from sand, ranges from five to nine _per cent._ Probably the
average proportion of true ash, viz.: that derived from the organic
matters themselves, not including sand and accidental ingredients, is
not far from five _per cent._

In twenty-two specimens of European peat, examined by Websky, Jaeckel,
Walz, Wiegmann, Einhof and Berthier, eleven contained from 0.6 to 3.5
_per cent._ of ash. The other eleven yielded from 5.3 to 22 _per cent._
The average of the former was 2.4, that of the latter 12.7 _per cent._
Most of these contained a considerable proportion of sand or soil.

Variation in the composition as well as in the quantity of ash is very
great.

Three analyses of peat-ashes have been executed at the author's instance
with the subjoined results:

ANALYSES OF PEAT-ASHES.
---------------------------+-----------+-----------+----------
| A. | B. |