f peat varies in
composition to an indefinite degree. Lime is the only ingredient that is
never quite wanting, and with the exception of sand, it is on the
average the largest. Of the other agriculturally valuable components,
sulphuric acid has the highest average; then follows magnesia; then
phosphoric acid, and lastly, potash and soda: all of these, however, may
be nearly or quite lacking.

Websky, who has recently made a study of the composition of a number of
German peats, believes himself warranted to conclude that peat is so
modified in appearance by its mineral matters, that the quantity or
character of the latter may be judged of in many cases by the eye. He
remarks, (_Journal fuer Praktische Chemie, Bd. 92, S. 87_,) "that while
for example the peats containing much sand and clay have a red-brown
powdery appearance, and never assume a lustrous surface by pressure;
those which are very rich in lime, are black, sticky when moist, hard
and of a waxy luster on a pressed surface, when dry: a property which
they share indeed with very dense peats that contain little ash. Peats
impregnated with iron are easily recognized. Their peculiar odor, and
their changed appearance distinguish them from all others."

From my own investigations on thirty specimens of Connecticut peats, I
am forced to disagree with Websky entirely, and to assert that except as
regards sand, which may often be detected by the eye, there is no
connection whatever between the quantity or character of the ash and the
color, consistency, density or any other external quality of the peat.

The causes of this variation in the ash-content of peat, deserve a
moment's notice. The plants that produce peat contain considerable
proportions of lime, magnesia, alkalies, sulphuric acid, chlorine and
phosphoric acid, as seen from the following analysis by Websky.

COMPOSITION OF THE ASH OF SPHAGNUM.

Potash. 17.2
Soda. 8.3
Lime. 11.8
Magnesia. 6.7
Sulphuric acid. 6.5
Chlorine. 6.2
Phosphoric acid. 6.7
_Per cent._ of ash, 2.5.

The mineral matters of the sphagnum do not all become ingredients of
the peat; but, as rapidly as the moss decays below, its soluble matters
are to a great degree absorbed by the vegetation, which is still living
and growing above. Again, when a stream flows through a peat-b