e shews that in every
100 parts of mulberry leaves, as supplied, the result is from 8 to 9
of worms, 36 to 40 of egested matters, and 45 to 46 of dry litter and
waste. That the sixth part only of what the worms consume tends to
their nourishment, the remainder goes in respiration and dejection;
and that, with the data now obtained, it is possible to calculate the
maximum weight of cocoons from a given weight of leaves--it being from
60 to 70 in 1000. He shews further, that in years when leaves are
scarce, the loss to the proprietors need not be total, for it is
possible to keep the worms on short allowance, and collect their
produce, though not so largely as when no privation exists. And what
is singular, that the weight of silk is not in proportion to the
weight of the worm or moth; heavy and light cocoons contain the same
quantity of silk, the difference arises only from the different weight
of the worms. Hence M. Peligot considers, that it would be well to
destroy the females when first hatched--of course with a reserve for
breeding--and keep only the males, which eat less, and give an equal
quantity of silk. But as yet the sexes cannot be distinguished, while
in the worm state.

You are aware that one of the most interesting geological problems of
our day is, that of the rise and fall of the land in Sweden: a good
deal has been said on both sides. The Academy of Sciences at Stockholm
has, however, taken measures to settle the question. It has chosen
sixteen stations, chiefly between Haparanda and Stroemstad, where daily
observations are made and recorded on the height of the sea. This is
the great point to be determined; hitherto, it has been left too much
to chance, or to the attention of casual travellers. In connection
with it, the rate of elevation would be ascertained, whether it is
everywhere the same, and continuous or intermittent. It has been
stated, that at Stockholm the rise was four feet in 100 years, and
greater still in the Gulf of Bothnia; but Mr Erdmann of Stockholm, in
a memoir on the subject, shews reason to doubt the fact. The house in
which he resides, standing near the port, was built at the beginning
of the seventeenth century; when the water of the adjacent sea is
raised two feet above the ordinary level, which happens but rarely,
his cellar is always flooded. Therefore, assuming the rise of the land
at four feet in the century, it follows, with only half that height,
that when the house was