venerable city, one of the oldest in the world,
situated at the base of the Ararat mountain
range, near the head-waters of the Euphrates,
and it was founded, as tradition says, by a
grandson of Noah. It is the Arz or Arza of ancient
times, which took the affix "room" from its
belonging at one period to the Greek Empire of
Room, thus becoming Erzeroom. It figures
largely in Armenian history; having for some
time been the capital of that ancient kingdom.
It contains at present about thirty-five thousand
inhabitants, who are principally Turks, most of
the Armenians having emigrated to Georgia at
the time of the Russian invasion. The city has
seventy fine streets, running in various directions,
which are broad for an Asiatic city, but very
filthy; and each street has its mosque and lofty
minaret, from whose tops the " Muezzins"
summon the " Faithful" five times a day to the
devotions of the Prophet. I do not recollect to have
heard the call to prayer at ten o'clock A.M., or at
four o'clock P.M., so regularly given in any other
Mohammedan city. Its houses are generally
built of earth, with occasional square sticks of
timber in the walls to give them support, though
many are built of fine hewn stone, There are
some remains of an ancient wall and fosse
around the city; but only the citadel is at
present fortified, and this is said to be the work of
the adventurous Genoese. The appearance of
Erzeroom is very sombre and uninviting, and,
from its great elevation-— five thousand five
hundred feet by the barometer, and near seven
thousand feet by experiments in boiling water,
above the level of the sea—- the weather, most
of the year, is extremely cold. As a residence
it must be dreary, though its climate, almost
as a matter of course, is healthy. The city
is well supplied with vegetables from gardens
near it; but has no fruit, except what is brought
a considerable distance from a more temperate
region. Its moral aspect struck us as even
darker than that of Trebizond, the people
appearing still more shy, rude, and degraded.

There are few objects of interest in modern
Erzeroom. The principal remnant of antiquity
which I observed, is the Jifteh Minereh (pair of
minarets), a vast stone building, finely
constructed, but now in a dilapidated state, which
is supposed to have been originally an
Armenian church, subsequently desecrated, as many
others have been, by the Mohammedans, and
surmounted by them with the two more modern
brick minarets, from which it bears its present
name. I also visited the largest mosque in the
city. It is an immense structure, but exhibits
only a mass of dead walls and pillars, with no
particular skill or taste displayed in their
erection. On the open space east of the city are
two circular stone towers of moderate size
and height, with conical roofs most admirably
constructed, evidently quite ancient, whose
origin and use are alike unknown. The
commerce of Erzeroom is immense-— its local
situation being exceedingly felicitious for transit
trade. It is the grand thoroughfare between
Europe, Asia Minor, and Syria, on the one hand;
and Persia, and, to a considerable extent, Georgia
and Mesopotamia, on the other. The city was
seriously injured in its commercial, as well as
its other interests, by the Russian invasion of
1829.

BONE-MAKING.

IN the year 1736, a London surgeon of the
name of Belcher dined with a dyer upon roast
pork. When the surgeon had eaten a piece of
the pork down to the bone, he was astonished
to find the bone coloured red. Asking his host
the cause of this extraordinary colour, he was
informed that the pigs fed upon the madder
refuse which they found cast out from tiie dye-
works, and it dyed their bones, and only their
bones. The muscles, the membranes, and even
the cartilages, were all of their ordinary colour,
but their bones were as red as soldiers' coats.
Mr. Belcher, who was an inquiring man, fed
a cock upon madder; and when the cock died
his bones were found to be red, while his
muscles, his membranes, and his cartilages,
retained their natural colour. Three years
afterwards, Duhamel, the physiologist, repeated and
verified the experiment of Belcher. The madder
had reddened the bones, but had not coloured the
cartilages which were growing into bones. But
Duhamel went further. After feeding a pig
with madder for some time, he fed it with its
ordinary food, and its bones displayed layers of
red covered by layers of white; and it was from
this experiment that Duhamel learned how the
bones grow in thickness by successive layers
laid over each other.

But this is not all that happens when bones
are growing. No doubt the bones grow in
thickness by the superposition of successive
layers so regularly, that, by an alternate diet of
madder and other food, red and white layers may
be made time about, and the time occupied by
each ring in growing ascertained exactly; but
there is another and a not less curious process
going on simultaneously. For our knowledge
of this process we are indebted to M.Flourens,
who repeated the experiments of Duhamel and
Belcher, and carried them much further. Some
twenty years ago, M. Flourens found that in.
proportion as the sides grew by the
superposition of external layers, the medullary canal
grew by the reabsorption of the internal layers.
The red circle begins by being outside; then it
is placed between two white rings; and then it
becomes innermost; and finally it disappears in
its turn. A different series of experiments leads
to the same results. A small bit. of platina wire
being twisted around a bone, after a little time
the ring is found inside the layers of bone, and
then within the medullary canal. Bones grow
thick, it thus appears, by a double process of
external superposition and of internal
reabsorption; aud just as they grow in thickness they
grow in length, by layers placed beside each
other, or in juxtaposition.

Duhamel held the opinion that a cartilage
was a thickened periosteum. Troja found, in