urred, M. Anozoff made experiments on the hardening of steel
instruments, by putting them, when heated, into a powerful current of
air, instead of quenching them in water. From the experiments already
made, he expects ultimate success. He finds that, for very sharp-edged
instruments, this method is much better than the ordinary one; that the
colder the air and the more rapid its stream, the greater is the effect.
The effect varies with the thickness of the mass to be hardened. The
method succeeds well with case-hardened goods.-- _From the French_.

_Detection of Blood_.

A controversy has recently taken place in Paris, relative to the
efficacy of certain chemical means of ascertaining whether dried spots
or stains of matter suspected to be blood, are or were blood, or not. M.
Orfila gives various chemical characters of blood under such
circumstances, which he thinks sufficient to enable an accurate
discrimination. This opinion is opposed by M. Raspail, who states, that
all the indications supposed to belong to true blood, may be obtained
from, linen rags, dipped, not into blood, but into a mixture of white of
egg and infusion of madder, and that, therefore, the indications are
injurious rather than useful.

_Cedars of Lebanon_.

Mr. Wolff, the missionary, counted on Mount Lebanus, thirteen large and
ancient cedars, besides the numerous small ones, in the whole 387
trees. The largest of these trees was about 15 feet high, not one-third
of the height of hundreds of English cedars; for instance, those at
Whitton, Pain's Hill, Caenwood, and Juniper Hall, near Dorking.

_Leeches_.

In the _Medical Repository_, a case is quoted, where some leeches, which
had been employed first on a syphylitic patient and afterwards on an
infant, communicated the disease to the latter.

_Stinging Flies_.

There is a fly which exteriorly much resembles the house-fly, and which
is often very troublesome about this time; this is called the stinging
fly, one of the greatest plagues to cattle, as well as to persons
wearing thin stockings.

_Mont Blanc_.

The height of Mont Blanc and of the Lake of Geneva has lately been
carefully ascertained by M. Roger, an officer of engineers in the
service of the Swiss Confederation. The summit of the mountain appears
to be 4,435 metres, or 14,542 English feet above the Lake of Geneva, and
the surface of the Lake 367 metres, or 1,233 English feet above the sea.
The mountain is, therefore, 1