Eureka daily sentinel. [volume] (Eureka, Nev.) 1871-1887, 1879-06-12
rrxsEnuNG MINES.
A Reliable Solution for the Prcser-
vafiau of Wood.

The importance Of a thoroughly reliable
protection of railway sleepers, the timber
ing in mines, and such like, has long been
recognized by engineers, and it is not
doubted that the far greater durability Sc
cured repays many fold the outlay which
has to be incurred. These preservative
processes have long been in use, but, &C.
cording to the mining Journal" none
have attracted more attention Of late than
that shown at the Paris Exhibition last
year, by messrs. Descaionne 4 Co., the es-
cntial feature Of which is the use OF salts
Of lead as the preservative agent, the adj
vantage Of which will be readily under
stord from a few very simple statements.
Commercially, the use Of plumbic salts for
these purposes may be regarded as alto
gether new, although in the laboratory
these preseryative properties are well
known. With regard to two of the leading
ingredients hitherto employed, it has been
very truly remarked that creosoting rem
ders the wood infiamable and gives it a
very disagreeable odor, while sulphate Of
copper not only does not properly improg-
nate the wood, but introduces into it a
portion Of %sulphuric acid, which disorgan-
ICES the vegetable fbres and has a de-
structive action on any nails or pieces OF
iron used in fastening the wood together.
Many other salts are equally Objectionable.
Tannate of iron bursts the woody cells,
chloride of zinc introduces a destructive
humidity, and baryta aud lime salts are
difficult to inject, and of very little value
when injected.
After considerable investigation and re-
search Messrs. Descalonne have adopted a
solution of which lead is the basis, and
which has given very satisfactory results.
One of the great advantages of lead is that
it does not oxidise in a damp atmosphere.
and they have found that they can prepare
a tarry tribasic plumbic salt, which is en-
tirely free from the defects mentioned.
Immediately it is injected it forms an in
soluble combination Of great solidity, and
p~etrifies everything in the wood that con-
tains the clements of decomposition. This
plumbic solution not only completely pro-
tects the wood from the attacks of insects
and vegetable parasites, but gives it a
hardness and strength which considerably
improves its durability, besides preventing
it from warping, swelling, or cracking.
For naval purposes, wood paving, tele-
graph posts, and the like, such an inven-
ton must prove Of great value, and the
Northern of France Railway nave made an
experiment with 5000 sleepers, from which
it appears that the plumbic solution is
superior to any preseryative hitherto
employed. In connection with mine tim
beers the continual eating way OF the pit
props used in coal mines, their high price
and other causes, have led TO experiments
being made with various antiseptic sub
stances, with a view, if possible, to increase
their durability.
Mr.. Fayol, a colliery engineer of Com
mentry, compared the relative value of
various compounds, and carefully recorded
his results, from which it appeared that al
though oak, beech, and pine sleepers were
rendered from 80 to 90 per cent. more
durable by the injection of the substances
which have previously been tested, there
was still much room for improvement and
i. was to the removal of such defects as
these that Messrs. Descalonne & Co.
turned their attention, with so much sue
cess that they were awarded a silver medal
by the French National Academy and a
gold medal by the Agricultural and In
sectologic Society Of France.