SUGGESTIONS IN THE IMPROVEMENT OF SLAUGHTER HOUSES. 
339 
structure, destroys its resistance, and transforms it 
into a substance, presenting many of the charac- 
ters of ulmic acid. These soluble substances also 
afford nutriment to the various insects or animals 
which destroy woods. 
The inference, naturally and necessarily to be 
drawn from these experiments was, that to pre- 
serve wood, these soluble matters must be altoge- 
ther removed, or rendered insoluble. The first of 
these was attended with difficulties that made it 
impracticable ; and all that was left, was to find 
some substance that would bring about the result. 
The impure pyrolignite of iron was fixed on, and 
appears, in the course of the experiments, to have 
fulfilled every purpose : the muriate of lime and 
common salt, also, were as efficacious in the pre- 
servation of wood, as the other salt, where the 
wood was not exposed to moisture. But a mode 
of introducing these solutions into the most remote 
fibres of the tree, was also to be devised ; and 
this led M. Boucherie to consider whether the 
usual circulation of the tree, did not continue after 
it was felled ; and whether this could not be em- 
ployed to carry the various matters with which he 
was experimenting. The idea proved a fortunate 
one, and met with entire success. Six days, in 
September, a poplar tree, ninety feet in height, and 
fifteen inches in diameter, the foot of which was 
immersed eight inches into a solution of pyrolignite 
of iron, was entirely impregnated by the liquid. 
The same result was produced when the tree was 
on the ground, and also before it was cut, by in- 
serting the fluid into excavations made in the 
trunk. A question presents itself, at this point, in 
the experiments, which it is important to decide — 
whether the absorbing power is the same at all 
periods of the year. It seems that there is no 
period in the year, in which the sap does not cir- 
culate. Even in winter, though not with so much 
strength as at other periods of the. year ; and what 
is, or appears to be singular, the spring, in which 
the circulation is, or is supposed to be, the most 
rapid and vigorous, is the least favorable time for 
the impregnation of the tree with these solutions, 
and autumn the best. Among the conditions neces- 
sary for success, one is, that the terminal foliage 
must be left on the tree, though all the other 
branches are removed ; and another, that as little 
delay as possible is admissible, before the impreg- 
nation of the tree has commenced. 
In the progress of these experiments, M. Bou- 
cherie has formed the conclusion, that the best 
time for felling timber, for its preservation, is the 
6ummer or autumn ; but the winter, the season 
which has been selected for ages for this purpose, 
he conceives the most pernicious. There is one 
thing wanting in these results — that is, to know 
how long wood will last after being thoroughly 
impregnated. A vessel' of war lasts, in time of 
war, eight years; in peace, fourteen. How, then, 
has M. Boucherie discovered a process by which 
these periods may be doubled ? In ships, where 
several hundred men are crowded together, the 
heated and bad air, must always affect the timber, 
and dispose it to decay. How is this to be pre- 
vented ? And if impregnation with a solution of 
pyrolignite of iron should do it, does it not render 
the wood so hard, as to make it extremely difficult 
to work ? The solutions of the other two salts, 
render wood pliable; but then, it must not De ex- 
posed to wet. Though, for all other building pur- 
poses, except ships, it would be made less liable to 
crack and gape, as it now does by the changeable 
character of our climate. No seasoning has ever yet 
been able to prevent these two deformities to 
house architecture, and so ruinous, too, to furni- 
ture. There still remains, apparently, a portion of 
water, perhaps absorbed from the atmosphere, even 
after every process has been gone through to expel 
it. A. L, Elwvn. 
Philadelphia. May, 1849. 
SUGGESTIONS IN THE IMPROVEMENT OF 
SLAUGHTER HOUSES. 
His Honor, Mayor Woodhull, of our city, in 
his late message, has suggested the establishment 
of public slaughter houses, upon a plan resemb- 
ling that of Paris. Under the present system of 
uncontrolled license, as is generally practised here, 
not only is our sight shocked and our olfactory 
organs offended by the too frequent occurrence of 
private slaughtering establishments, but, moreover, 
a mightier consideration is neglected — the pi ,r ity 
of the article vended can with no certainty be 
determined. We insert, for the benefit of our 
readers, the following remarks on the method of 
arrangement and construction, adopted by the 
Parisians in the matter of their abattoirs, and the 
manifold advantages arising therefrom, wfcteh we 
most sincerely recommend to the attention of all 
our cities and populous towns : — 
All meat, from animals slaughtered within the 
limits of the city of Paris, is prepared for market 
under the immediate supervision of municipal 
officers, at four great abattoirs, (slaughter houses,) 
situated in distant and unfrequented sections of 
tne town, and most generally upon very elevated 
ground. The buildings, used for the purpose, 
are situated within a public park, near the magni- 
tude of Washington square, in New York, sur- 
rounded by a wall, and entered only through one 
large gateway. At the portal, stand the officers, or 
the persons employed in the supervision of the 
establishment. As each animal is brought in, it 
is carefully weighed, registered, and a veterinarian 
examines its condition. If pronounced diseased, 
it is either condemned or consigned to a species of 
hospital within the grounds. Every carcass, after 
being in due manner operated upon, is weighed 
and examined, in like manner, before leaving the 
gates; the government being thus responsible to 
the butcher to render him an account of the pro- 
ducts of his labor in meat, grease, hides, and even 
the offal. The cattle are kept in stables, each 
holding about a hundred head, rivalling in clean- 
liness those of a racing stud ; the beasts are, 
moreover, permitted to graze within the enclosure, 
and are led to drink at large fountains of perpetu- 
ally flowing water. The slaughter houses arc 
detached, and at some distance from each other. 
The animals are killed, either by butchers em 
ployed by the municipal authorities, or the ownei 
can hire a portion of one of these general build- 
ings for his own use, subject to the official super- 
vision. 
After being killed, the smaller animals are skin- 
