compact sandstone, appears to have resulted from a deficiency in the
supply of air, in consequence of the smallness of the cells, and the
impermeable nature of the stone; the larger volume of air originally
inclosed in the cells of the limestone, and the porous nature of the
stone itself, (permeable as it is slowly by water, and probably by air,)
seem to have favoured the duration of life to the animals inclosed in
them without food.

"It should be noticed that there is a defect in these experiments,
arising from the treatment of the twenty-four Toads before they were
inclosed in the blocks of stone. They were shut up and buried on the
26th of November, but the greater number of them had been caught more
than two months before that time, and had been imprisoned all together
in a cucumber frame placed on common garden earth, where the supply of
food to so many individuals was probably scanty, and their confinement
unnatural, so that they were in an unhealthy and somewhat meagre state
at the time of their imprisonment. We can therefore scarcely argue with
certainty from the death of all these individuals within two years, as
to the duration of life which might have been maintained had they
retired spontaneously, and fallen into the torpor of their natural
hibernation in good bodily condition.

"The results of our experiments amount to this: all the Toads, both
large and small, inclosed in sandstone, and the small Toads in the
limestone also, were dead at the end of thirteen months. Before the
expiration of the second year all the large ones also were dead; these
were examined several times during the second year through the glass
covers of the cells, but without removing them to admit air; they
appeared always awake, with their eyes open, and never in a state of
torpor, their meagreness increasing at each interval in which they were
examined, until at length they were found dead; those two also which had
gained an accession of weight at the end of the first year, and were
then carefully closed up again, were emaciated and dead before the
expiration of the second year.

"At the same time that these Toads were inclosed in stone, four other
Toads of middling size were inclosed in three holes, cut for this
purpose on the north side of the trunk of an apple-tree; two being
placed in the largest cell, and each of the others in a single cell.
The cells were nearly circular, about five inches deep and three inches
in diamete