ficial geological student. We are
only able to investigate the crust of the earth, with all our
ingenious boring instruments: but even in this crust we may trace a
gradual change, and recognise the silent operations of nature in ages
never counted by man. According to the popular theory, the earth must
have been sixty times as large as its present size, and have cooled to
its present dimensions, retaining still, in its unfathomable bowels, a
burning heat. The conclusions of geologists, after long and patient
examination, are, that certain rocks mark the age of the world--that,
in fact, the crust of the globe consists of a certain number of
strata, each belonging to a certain era, as the rings of a tree tell
its years of growth. The more they test this theory, the more certain
are they that the history of our globe may be accurately read in the
strata which compose its crust. "A granitic crust, containing vast and
profound oceans, as is proved by the extent and thickness of the
earliest strata, was the infant condition of the earth. Points of
unconformableness in the overlying aqueous rocks, connected with
protrusions of granites, and other similar presentments of the
internal igneous mass, such as trap and basalt, mark the conclusions
of subsequent sections in this grand tale. Dates, such as
chronologists never dreamed of--compared with which, those of Egypt's
dynasties are as the latter to a child's reckoning of its
birthdays--have thus been presented to the now living generation, in
connexion with the history of our planet."[5] These changing masses
have been discovered with remains of organic life wrapped in their
particles, each mass enclosing a petrified museum of the life that
flourished while it was in course of formation: thus not only have we
distinct proof of extinct forms of animal and vegetable life, but we
are also able to assign the dates of their existence.

The MOST EASTERLY ROOM of the NORTHERN MINERAL and FOSSIL GALLERY, is
that to which the visitor's attention will be first directed. In this
room, as in the next three, the table cases are devoted to the
minerals; and the wall cases, along the southern side of the gallery,
are filled with

FOSSIL VEGETABLES.

The wall cases of this room contain the various strata which have
traces of vegetable life. The earliest vegetable life of which the
geologist has found fossil remains is in the form of sea-weeds,
specimens of which the visitor will notice in