of the
German empire, in Poland and Prussia, and still more in Norway, Sweden,
and the vast empire of Russia--can we see what Europe was before it
yielded to the power of Rome. Desolation now reigns where stately
forests of pine and oak once flourished, such as might now have supplied
all the navies of Europe with timber.

_Sources of bog iron-ore._--At the bottom of peat-mosses there is
sometimes found a cake, or "pan," as it is termed, of oxide of iron, and
the frequency of bog iron-ore is familiar to the mineralogist. The oak,
which is so often dyed black in peat, owes its color to the same metal.
From what source the iron is derived has often been a subject of
discussion, until the discoveries of Ehrenberg seem at length to have
removed the difficulty. He had observed in the marshes about Berlin a
substance of a deep ochre yellow passing into red, which covered the
bottom of the ditches, and which, where it had become dry after the
evaporation of the water, appeared exactly like oxide of iron. But under
the microscope it was found to consist of slender articulated threads or
plates, partly siliceous and partly ferruginous, of what he considered
an animalcule, _Gaillonella ferruginea_, but which most naturalists now
regard as a plant.[1011] There can be little doubt, therefore, that bog
iron-ore consists of an aggregate of millions of these organic bodies
invisible to the naked eye.[1012]

[Illustration: Fig. 101.

_Gaillonella ferruginea._

_a._ 2000 times magnified.]

_Preservation of animal substances in peat._--One interesting
circumstance attending the history of peat mosses is the high state of
preservation of animal substances buried in them for periods of many
years. In June, 1747, the body of a woman was found six feet deep, in a
peat-moor in the Isle of Axholm, in Lincolnshire. The antique sandals
on her feet afforded evidence of her having been buried there for many
ages: yet her nails, hair, and skin, are described as having shown
hardly any marks of decay. On the estate of the Earl of Moira, in
Ireland, a human body was dug up, a foot deep in gravel, covered with
eleven feet of moss; the body was completely clothed and the garments
seemed all to be made of hair. Before the use of wool was known in that
country the clothing of the inhabitants was made of hair, so that it
would appear that this body had been buried at that early period; yet it
was fresh and unimpaired.[1013] In the Philosophical Tra