s brief notice of those organic _compounds_ that have been
recognized in or produced from peat, we may give attention to the
elementary composition of peat itself.

Like that of the vegetation from which it originates, the organic part
of peat consists of Carbon, Hydrogen, Oxygen and Nitrogen. In the
subjoined table are given the proportions of these elements as found in
the combustible part of sphagnum, of several kinds of wood, and in that
of a number of peats in various stages of ripeness. They are arranged in
the order of their content of carbon.

-----------------------------------+----------+-----+-------+-----+-------
| |_Car-|_Hydro-|_Oxy-|_Nitro-
|_Analyst._|bon._| gen._ |gen._| gen._
-----------------------------------+----------+-----+-------+-----+-------
1--Sphagnum } | Websky |49.88| 6.54 |42.42| 1.16
2--Peach wood } undecomposed |Chevandier|49.90| 6.10 |43.10| 0.90
3--Poplar " } | " |50.30| 6.30 |42.40| 1.00
4--Oak " } | " |50.60| 6.00 |42.10| 1.30
5--Peat, porous, light-brown, | | | | |
sphagnous | Websky |50.86| 5.80 |42.57| 0.77
6-- " porous, red-brown. | Jaeckel |53.51| 5.90 | 40.59
7-- " heavy, brown. | " |56.43| 5.32 | 38.25
8-- " dark red-brown, | | | | |
well decomposed | Websky |59.47| 6.52 |31.51| 2.51
9-- " black, very dense | | | | |
and hard. | " |59.70| 5.70 |33.04| 1.56
10-- " black, heavy, }best quality| " |59.71| 5.27 |32.07| 2.59
11-- " brown, heavy, }for fuel. | " |62.54| 6.81 |29.24| 1.41
-----------------------------------+----------+-----+-------+-----+-------

From this table it is seen that sphagnum, and the wood of our forest
trees are very similar in composition, though not identical. Further, it
is seen from analyses 1 and 5, that in the first stages of the
conversion of sphagnum into peat--which are marked by a change of color,
but in which the form of the sphagnum is to a considerable extent
preserved--but little alteration occurs in ultimate composition; about
one _per cent._ of carbon being gained, and one of hydrogen lost. We
notice in running down t