latitude, and hence in climate, is, in the present state of our
knowledge, rather an argument against than for their having existed
cotemporaneously. The _Cycadeae,_ especially, whose fossil
remains afford so much ground for geological speculations, are far
from yielding such precise data as is supposed. Species of the order
are found in Mexico, South Africa, Australia, and India, some
inhabiting the hottest and dampest, and others the driest climates on
the surface of the globe; and it appears to me rash to argue much
from the presence of the order in the coal of Yorkshire and India,
when we reflect that the geologist of some future epoch may find as
good reasons for referring the present Cape, Australian, or Mexican
Flora to the same period as that of the Lias and Oolites, when the
_Cycadeae_ now living in the former countries shall
be fossilised.

Specific identity of their contained fossils may be considered as
fair evidence of the cotemporaneous origin of beds, but amongst the
many collections of fossil plants that I have examined, there is
hardly a specimen, belonging to any epoch, sufficiently perfect to
warrant the assumption that the species to which it belonged can be
again recognised. The botanical evidences which geologists too often
accept as proofs of specific identity are such as no botanist would
attach any importance to in the investigation of existing plants.
The faintest traces assumed to be of vegetable origin are habitually
made into genera and species by naturalists ignorant of the
structure, affinities and distribution of living plants, and of such
materials the bulk of so-called systems of fossil plants is composed.

A number of women were here employed in making gunpowder, grinding
the usual materials on a stone, with the addition of water from the