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[ClIiCULAR No. 9.]
United States Department of Agriculture,
EFFECT OF TURPENTINE GATHERING ON THE TIMBER
OF LONGLEAF PINE.
In Circular 8 of the Forestry l)ivi.sioii, published about a year ago, it was stated
that tests made on timbers of Longleaf Pine, bled or unbled, lent countenance to
the belief that bled or tapped timber did not sutler in strength by virtue of the
tapping. Further tests and examinations permit now the announcement without
reserve that the timber of Longleaf Pine i.s in no irn.i/ affected bi/ the tapj>tnr/ for turpen-
tine. This refers to its mechanical as well as chemical pro]ierties, and hence even
the reservation that it migiit suffer in durability is now eliminated and any preju-
dice against the use of bled timber in construction, wherever the unbled timber
has been considered desirable, must fall as having no found;ition in fact, i)eing
based only on vague belief, proved to be erroneous.
It is to be hoped that this fact will be made widely known among builders,
architects, and engineers who have hitherto made discrimination against bled tim-
ber and thereby depreciated or discouraged the manufacture and impeded the sale
of an article which answers all the purposes of construction and the unrestricted
use of which is dictated by true economy.
The basis for the statement i-egarding the mechanical ijroi>erties is furnished
by a series of tests comprising not less than 300 tests on 32 trees of this Pine, l)led
and imbled, from various localities.
The somewhat puzzling fact that bled timber exhibited, if anything, greater
strength in the tests has been accounted for by the fact that the turpentine
orchards are located mostly on sites which produce better quality timber as well
as larger yield of tui'pentine.
To determine whether any changes in the chemical composition take jslace, a
series of chemical analyses of bled and unbled timber has been made, which
indicates that the resinous contents of the heartwood are in nowise affected by
the bleeding, the oleoi'esins of the heartwood being non-fluid, the whole turpentine
tiow is confined to the sapwood.
Among other interesting facts regarding the distribution of resinous contents
through the tree which will be published in a separate bulletin, it ajipears that
trees standing side by side and to all appearances in similar conditions show very
varying quantities of resinous contents.
To make sure that experience did not, if sifted down, contradict the results
of these investigations, a competent agent, Mr. F. Eoth, visited turpentine orchards
and sawmills in the Longleaf Pine region. He reports that nobody was found —
although it was claimed by some — able to discern any difference in "the appearance
of the bled and unbled timber ; that in spite of consumers' specifications for
unbled timber, they are almost invariably served with a mixture without finding
it out ; that experience in the districts where bled timber is cut and used has not
sustained the claim of inferiority.
This information is furnished in advance of the full report on the investiga-
tions in question, in order to remove as quickly as possible the unwarranted dis-
crimination against the product of nearly one million acres of Southei'n pine,
which are annually added to the total acreage in turpentine orchards.
This result of authoritative investigation should be worth several million dol-
lars to the forestry interests of the South, permitting readier use and sale for a
product that left uncut endangers the future of the forest by the destructive
conflagrations to which it is specially subject.
B. E. Feknow,
CJdef of Difuision.