Gloucester County Democrat. (Woodbury, N.J.) 1878-1932, 1901-01-10
aas 49,
AG17lRMo F0gAO
~ aNh GARDEN
CRUDE PETROLEUM.
One Theory of It's Effects when Used
Against San jose Scale.


One Theory of It's Effects when Used
Against San jose Scale.
Crude petroleum as an insecticidc is
very recent, and that it would require
some time to ascertain its exact range
of usefulness must seerl reasonable to
those who remember that paris green,
now in universal use. was long opposed
as dangerous to both plants and con-
sumers Of plant products and that the
range of its usefulness was not estab-
lished for many years if indeed it can
be said to be fixed even now. Paris
green is fatal to certain class of in
sects and is also fatal to plants. but
there is margin of safety in the diff
ference between the amount which is
fatal to insects and the amount fatal to
plants; hence we use it as an insecti-
eide. This margin OF safety is not the
same for all kinds of vegetation. and in
some cases it disd Ppea-,5 altogether, the
plant being more sensitive to the poi
son than the insect infesting it. To
learn all this has required years of ex-
pertinent and experience at a cost OF
many dead plants and many lost crops.
So it must net be considered as a dis
enlargement if some injury is caused
by this new product.
My own experiments had been so uni
formly safe and successful that the uI2
satisfactory outcome in a number Of
cases seemed incomprehensible until
carefully investigated. 1t was found.
first of all, that many of those who had
used the oil and suffered injury had
done so without ever having seen or
read anything concerning the method
OF It's use. Others had used it without
any regard to the question whether the
tree needed it or not or had been capti-
yated by the Incidental result reeeHfie-l
as f9ffewed : ig0r In tFcate-ltrees.
There were enough other cases of in
Jury seen, where oil was iiltelligently
used. to direct attention to the material
itself, and it was then found that the
term "crude petroleum" had no definite
meaning in the trade; that in some
cases reduced OIL fuel OIL or ''in-
termediate oil'' had been sold and ac-
cepted as crude oil and that Il straight
crude" was the exception rather than
the rule. When my attention was
drawn to the differences in so called
''crude petroleum. | first Of all tested
the material with which my own eX-
periments were made and founu that
it had a specific gravity of 43 degrees
on the Beaume oil scale. II color it was
dark green. No other oil used. as far
as tested by me. registered higher than
this, but much of it was decidedly low
er, some intermediate" as low as 30
degrees. The latter was almost uni
ferrnly fatal. and On trees ON which /
applied it myself in exactly the way l
used the straight crude it killed peach,
plum and cherry. Afterward l secured
q sample of an Gil that had killed n
number of peach trees at White House,
N. ]. This had a specific gravity of
3I6 degrees and was reported by a
chemist as probably mixed crude and
distillatc Further inquiry showed that
even straight crudes differed widely in
color, in specific gravity and in other
ways. From the Pacific coast | receiv-
ed letters claiming that to spray crude
oil undiluted was an impossibility, and
some of my eastern correspondents
made similar claim.
From West Virginia Professor Hop
kins of the experiment station reported
results with crude oil fully sustaining
nv own conclusions and. as the oil
used by his constituents came from the
fields near by. 1t was determined that
I should visit this locality to ascertain
if possible just what sort of oils could
be best used for insectlcide purposes.
From personal observation and in
formation obtained 1t seems that nat
uraI crude oils do comparatively little
injury to vegetation unless the applica-
ton is very excessive or long contin-
ued. From almost every we'll there is
some overflow down hill m n fairly de-
fined channel All vegetation is killed
in this channel, but trees and shrubs
may grow at its edge. 1t was the testi-
mony of all with whom | spoke that
when wells were shot and oil soaked all
the trees round about there was injury
in exceptional cases only. The oils test
ed by me ran high. reach,-.y 4I.o de-
grees In specific gravity.
Perhaps this is a good place to note
that even in straight crudes there is
considerable range III specific gravity.
In the report of the West Virginia geo.
logical survey for 1880 the specific
gravity of 90 different samples of oils
is given. all from different wells. The
lowest of these is 3415 degrees and is a
green oil. only one well giving SO low
reading. From past experience this
world lie dangerous oil to use for in
secticide purposes One well yields
black oil. specific gravity 80 degrees;
one well a green oil 20 degrees. and
two wells a green OIL. 39ls degrees. All
of these would be dangerous to plant
life One green oil runs 10 degrees,
two green and two amber oils run Al
degrees. and all of these might he
harmful on peach or plum trees. Thus
10 samples out of So would have to be
rejected for insecticide purposes unless.
being mixed with lighter oils. the spe-
cific gravity is brought above the dan
rer line. Oils of ~ degrees and up
ward may be considered safe The
highest sample listed is one of 63la de-
rrees. end this is an amber oil. Thir-
teon SAMPLES register 80 degrees or
over. leaving 20 that run between 40
ana 40 degrees. the majority running
nearer to 4j degrees than to A degrees
both in green and in amber. It is
fair requirement, then. for straight
cy,.,e petroleum that it should have
snecffie gravity of AZ degrees or over
af . temperature of 60 degrees F. Any
thing less might be harmful anything
.,,ore Than a degrees is unnecessary.