The evening times. [volume] (Grand Forks, N.D.) 1906-1914, 1907-02-23
SATURDAY, FEBRUARY %, 1907.

to be revealed in q distillation test.
such as prescribed by the state law.
This test will show in such an oil a
high per cent of distillates below 80
degrees or high per cent of residual
oil remaining above $50 degrees, or an
excess of both. An oil made up In
this way of large amount Of mixed
oils usually gives a good light at the
start, but after n certain period. when
this light oil has burned of, the flame
usually diminishes rapidly and mate
rally in size and brilliancy, and the
combustion from that time Is slower,
the light less, and the tendency TO
smoke and encrust the wick greater.
The best oil made from the entire cut
does not show large amount OF light
oil, distilling below $40 degrees, nor
large residual oil Remaining when
heated to $40 degrees. Almost all Of
such high grade oil lies between
these two limits. Such an oil of the
entire cut gives our best illuminating
results. 1t burns with a very even
flame, diminishing only gradually as
the oil is exhausted.
Attention is directed to an illustra-
ton of this fact in the oils which were
subjected to the photometric and dis
tillation tests. While the distillation
ests, as already stated, are of great
value, they require well-adjusted ap-
paratus and considerable time and skill
in carrying them on, which can only be
successfully secured at the laboratory.
AS large a number of oils as possible
should be subjected to the distillation
tests. Special apparatus has been de-
vised and utilized in this laboratory
for rapid and accurate determinations
of the distillate and residue.
Sulphur.-Sulphur is Objectionable
in kerosene oil because it materially
reduces the Illuminating power and
also because, when the oil burns, the
sulphur is converted into gases which
are corroding and otherwise objection
able impurities In the air. Crude Pc
troleum from different regions varies
somewhat in the amount of sulphur 1t
contains, and due to this and to the
variation in methods Of production
there is considerable difference in the
sulphur left in kerosene oil. Our pres
ent law does not mention specifically
the limits. A. good kerosene should,
however, not contain more than .005
Of one per cent sulphur. It will be
seen by the following analyses that
large proportion of samples analysed
were within these limits. 1t is desira-
BILE to keep the sulphur down as low as
possible.
PhOtometric Photometric tests
are mentioned in our state law, but
no definite figures are prescribed.
These tests are of great value in that
they reveal the Illuminating value in
actual candle power. The illuminate
ing power is, of course, next to safety,
the most important requisite of kero-
sene.
Accurate photometric tests require
very delicate instruments, special test
ing apartments, and demand much
care. skill and time if reliable results
are to be secured. The university Is
ment of physics one of the best made
German photometers. The photomet-
ric determinations given in this report
have been made with this instrument
by DR.. G. w. Stewart, professor Of
physics. DR.. Stewards determinations
were made with great care and skill.
AS will be seen later, the results OBJ
tanned and the samples tested show
the actual Illuminating power to be
very similar to what would be expect
ed by Interpretation of the other chem
ical and physical tests. 1t is desira-
BILE to secure as many photometric
tests as possible on the different
grades and brands of oils on the mar
ket.
The accompanying tables are the re-
suits of the analyses and physical tests
made on oils and gasolines at the uni
versity and school of mines All of
these analyses and tests, with the ex-
ception Of the photometric tests. were
made by the writer in the chemical
laboratories of the university and
school of mines.
From the analysis and tests given,
it will be seen that IT'S per cent OF
oils tested fell below the requirements
of the law in one or more particulars
sulphur not considered).
These results show that there is
lower proportion of oils which pass
the state requirements than there
should be. However, it may be seen
that In a large number of cases the
failure was by only a small margin,
In other words, many of those which
are included in the us per cent
which failed in some point, came very
near to the passing point. There is,
however, still a large percentage of
oils which fell decidedly below the
requirements of the law. On the whole
it may be said that since this. more
rigid inspection began about two years
ago, there seems to be somewhat of
an improvement in the grades mar
keted. There is room, however. for
much more Improvement.
These figures illustrate very clearly
the point, which has already been
mentioned in this paper under speci-
nc gravity, namely, that it is an easy
matter to so proportion the oil to pass
the gravity test Therefore this is the
least important Of the tests prescribed
1t Will he seen that 40 per cent
OF the oils failed to pass the flash
test. While several of these were
within degree of the required stand
ard there was. however, too large a