earth, is proved by comparing the fossil club mosses, which have been found as large as beech trees, whereas at the present time the most gigantic club moss rarely exceeds three feet in height.  In the lower sections of the third, fourth, and fifth cases, the visitor may notice some fine specimens of polished fossil woods; but the varieties of vegetable fossils can hardly engage his serious attention for any length of time, unless he have some real knowledge of botany and geology; yet he may gather the solemn teaching that lies in those dark masses of early coal formation and clay slate, even though he be unable to explain the first principles of botanical science.  He may notice, however, in the fifth and sixth wall cases, fossil specimens of extinct plants, including the sigillaria, which, when living, is supposed to have attained often to the height of seventy feet.  Having noticed these vegetable remains, the visitor should cross to the northern wall of the room, and examine the sandstones upon which the tracks of an extinct animal called the chirotherium—­and footprints, supposed to be of birds, are distinguishable.

The central object in the room is a tortoise found in Hindostan, near Allahabad.  It is carved out of nephrite or jade, and is deposited upon a curious table of inlaid ancient marbles.  Against the eastern wall are deposited some beautiful varieties of branched native silver from Norway; Lady Chantrey’s specimen of part of a coniferous tree, semi-opalised; and a mass of websterite from Newhaven, Sussex.  The table cases now remain for examination.  These are devoted to varieties of

Minerals.

and their combinations.  The visitor should examine the cases in the order in which they are arranged, beginning with the cases marked 1 and 1A.  These two cases contain specimens of native Iron.  Native iron has nearly always proved to be of meteoric origin; and the specimens are here arranged in the order in which they have been found.  They have fallen from the heavens at different places, and at different periods.  The largest known aerolite is that which fell in Brazil, and was no less than eight feet in length.  These huge solid masses of iron, discharged from the clouds in a burning state, may well set the brains of philosophic men to work, to unravel the splendid mystery that contrives laboratories high up in the air, from which dense tons of pure iron are discharged upon our earth.  Humboldt, discarding the Laplaceian theory that aerolites were detached masses of the moon, which ignited on reaching the oxygen that surrounds our globe, asserts that they are Lilliputian planets, having their system as we have ours; that they are identical with shooting stars, and that they occasionally fall to the earth by coming within the attraction of a body of overpowering magnitude.  In the case with these meteoric specimens of native iron are specimens of native Copper—­not often found in a pure state; native Lead, of meteoric origin; one specimen, exhibited in the form of a medal, having been cast out of the crater of Vesuvius about two hundred years ago; and native Bismuth, which expands as it cools.