Gloucester County Democrat. (Woodbury, N.J.) 1878-1932, 1906-08-23
THE USE OF CARBOIIC ACID As AN
INSECTICIDE.

There is an 1ncllnatlOn--iocatly- 10 pus
considerable faith in the application Of
crude carbolic acid as a corrective to the
ravages of the San Jose scale.
There is, possibly, not one in hundred
Of those who have tried this material who
are at all familiar with the properties OF
elemental principle contained in the solu-
ton they are purchasing. Carbolic acid
Tor, more correctly, s'Phenol hydrate' J
varies considerably as to value. In the
production Of Illuminating gas, some grades
of coal will yield product carrying 20 to
80 per cent. phenol, while other coal will
yield as low as 5 to per cent. phenol-
the toxical principle Of coal-tar Liquor
volatilizes freely at temperatures above 50
degrees Fahr.; hence the application of this
material should be made by forminga union
with some substance capable OF absorbing
and holding the phenol for the greatest
length Of time.
There are various materials having this
infusing quality, but, owing to their nature
Of forming an oxidized film on the surface
OF whatever applied to, they would SOON
smother any trees treated to such applica-
ton, therefore care must be used in the
selection Of the absorbent.
There are several bodies chemically
termed fixing agent" Two of the best
and most stable are lime and salt. It is
not necessary here to outline why they are
20 in general, but 20 give the correct reason
why they should be used as retainers to
absorb and hold the active principle for
which carbolic acid is used.
First Calcium hydroxide (slaked lime)
is positive and unchanging wherever APP
piled in the open atmosphere. 1t may
wash off in time, but it is still the same.
Second The properties of lime towards
a union-both homogeneous and smoothly
fluids well known and appreciated by
every one.
Third-Taking calcium carbonate (un-
Stacked lime), adding to it water in suffi-
cient quantity, produces the intensely high
temperature through the uniting of two
elements.
Fourth At the time that the lime is
actively shaking, if-instead Of adding more
understandable acid is substituted (as high
in strength as possible) in quantity equiva
lent to gallon Of acid for each 40 pounds
of lime used, a portion Of the phenoi hy-
drate will be changed to phenol hydroxide
just what PERCENTAGE, would lay with the
strength Of the acid used, but sufficient to
yield product caustically astringent and
retaining its insecticidal properties for far
greater space of time than the application
Of the simple coal-tar liquor is capable of,
owing to its volatile nature
The probability is that carbolic acid
simply acts the same as all insecticides that
have been tried. 1t is temporary remedy,
subject to continued use. But there is this
much in its favor. It is an intensely caus-
tic poison, and where used as suggested
and the treatment reduced to spraying
operations the solution will be just as eff
fective as the stronger application of the
plain carbolic acid, which will unqestion-
ably volatilize all of the poisonous princi-
pie in "a hours, and simply leave an inert
tar film on the trees.
The theory has been advanced that the
carbolic acid enters in the trunk of the tree
and flows upward with she sap. Nearly
every resinous extractive matter is soluble
in and completely transformed in solutions
of carbolic acid. and. as the sap of the tree
is simply the fald resinous property of the
tree, this assumtion IS entirely fallacious.
Whatever effect is produced from the use Of
this material, it is surface result and no
other.
1t is commendable to try-and to keep
on .rying-until some definite resultiYe
method is reached, to overcome this scale;
but, so far as the writer has observed, the
solutions presently employed haYe been
quickly subject to atmospheric changes, or
Of an underminate chemical construction,
like the lime, sulphur and salt combination
which was undoubtedly advanced with
sulphur as the active insecticide, and the
lime and salt as the fixing agents, the re-
sulting mixture being Of an entirely TN
known quantity.
/ To the writer's mind, this problem re-
solves into some treatment that will coyer
the entire tree with porous corrosive film
not quickly subject to change-some strict
attention by all property owners to the de-
struction Of all brush or hedge-rows infested
with the scale, thus giving any treatment a
more effective opportunity to destroy the
pest on more valuable trees, and not be
forced to constant renewals from these
fence-rows.i FRANK BIRD.
Stanton, N. J., Aug, II, 1906.
PAuLsHoRo.