FERN LEAVES, AND OTHER COMBUSTIBLE MATERIALS.

[Footnote: Abstract of a paper read before the Franklin Institute,
April, 1887.--_J.F.I._]

By A.E. OUTERBRIDGE, JR.


The art of making charcoal--if, indeed, so crude a process is worthy of
being dignified by the name of an art--dates back to a remote antiquity,
and has been practiced with but little change for hundreds of years. It
is true that some improvements have been recently made, but these relate
to the recovery of certain volatile by-products which were formerly
lost.

Every one is familiar with the appearance and characteristics of
ordinary charcoal, yet I hope to show you this evening that we still
have something new to learn about its qualities and the unexpected
practical uses to which it may be applied.

We commonly regard charcoal as a brittle, readily combustible substance,
but we have before us specimens in which these qualities are
conspicuously absent. Here is a piece of carbonized cotton sheeting,
which may be rolled or folded over without breaking, and, as you see,
when placed in the flame of a Bunsen burner, the fibers may be heated
white hot in the air, and when removed from the flame, the material
shows no tendency to consume. Here, again, we have a piece of very fine
lace, which has been similarly carbonized, and displays the same
qualities of ductility and incombustibility.