The name of Dr. Boucherie is generally applied to the _process_, which
he invented and extensively applied, of preparing wood by forcing a
solution longitudinally through the pores of the wood by means of
hydraulic pressure. As, however, he also patented the use of sulphate of
copper, and his name became attached to the use of that antiseptic, it
will be convenient here to classify experiments made with that substance
under this head.
Dr. Boucherie was a distinguished French chemist, who between 1836 and
1846 made many elaborate researches and experiments upon the
preservation of timber. He tried many substances, and at first
recommended the use of pyrolignite of iron, but subsequently used
sulphate of copper, which he considered more effective.
His first experiments were conducted by vital suction, that is, by
tapping the living tree, and allowing the ascending sap to carry up a
preserving solution. This was not found to give uniform or satisfactory
results, and Dr. Boucherie then invented the process which bears his
name. This was practiced either by applying a cap to the end of a
freshly cut log, through which the solution was allowed to flow by
pressure, or by sawing a log nearly through in the middle, raising it at
the center slightly, so as to open the joint, placing a strip of tarred
rope or a rubber band just inside the periphery of the cut log, and
letting it spring back, so as to form a tight joint by pressing upon the
rope or band. An auger hole bored diagonally into the cavity so formed
then served to admit the solution under pressure.
This process, applied with a solution of about one pound of sulphate of
copper to one hundred pounds of water, has been extensively applied in
France for many years, with satisfactory results. It was found, however,
that to be successful it must be applied to freshly cut trees in the log
only, and that this involved so much delay, moving about, waste, and
annoyance, that it has now been abandoned. These difficulties would be
still greater in this country, and in the Northern States the process
could not be applied at all during the winter (or season for cutting
down trees), as the solution would freeze.
On this page is a list of the experiments which your committee have been
able to learn about, as having been made with sulphate of copper in this
country.