[Footnote 1: Report to the United States Internal Revenue Department
by C.A. Crampton, Chemist of U.S. Internal Revenue; H.W. Wiley, Chief
Chemist of U.S. Department of Agriculture; and O.H. Tittmann,
Assistant in Charge of Weights and Measures, U.S. Coast and Geodetic
Survey.]
Section 1, paragraph 231, of the act entitled "An act to reduce
revenue and equalize duties on imports and for other purposes,"
approved October 1, 1890, provides:
"231. That on and after July 1, eighteen hundred and ninety-one, and
until July 1, nineteen hundred and five, there shall be paid, from any
moneys in the Treasury not otherwise appropriated, under the
provisions of section three thousand six hundred and eighty-nine of
the Revised Statutes, to the producer of sugar testing not less than
ninety degrees by the polariscope, from beets, sorghum, or sugar cane
grown within the United States, or from maple sap produced within the
United States, a bounty of two cents per pound; and upon such sugar
testing less than ninety degrees by the polariscope, and not less than
eighty degrees, a bounty of one and three-fourth cents per pound,
under such rules and regulations as the Commissioner of Internal
Revenue, with the approval of the Secretary of the Treasury, shall
prescribe."
It is the opinion of this Commission that the expression "testing ...
degrees by the polariscope," used with reference to sugar in the act,
is to be considered as meaning the percentage of pure sucrose the
sugar contains, as ascertained by polarimetric estimation.
It is evident that a high degree of accuracy is necessary in the
examination of sugars by the Bureau of Internal Revenue, under the
provisions of this act, inasmuch as the difference of one-tenth of one
per cent. in the amount of sucrose contained in a sugar may, if it is
on the border line of 80°, decide whether the producer is entitled to
a bounty of 1¾ cents per pound (an amount nearly equivalent to the
market value of such sugar) or to no bounty whatever. It is desirable,
therefore, that the highest possible degree of accuracy should be
secured in the work, for while many sugars will doubtless vary far
enough from either of the two standard percentages fixed upon in the
act, viz., 80° and 90°, to admit of a wide margin of error without
material consequences, yet a considerable proportion will approximate
to them so closely that a difference of a few tenths of a degree in
the polarization will change the classification of the sugar.
A very high degree of accuracy may be obtained in the optical
estimation of sugars, if the proper conditions are observed. Such
conditions are (1) accurately graded and adjusted instruments,
weights, flasks, tubes, etc.; (2) skilled and practiced observers; (3)
a proper arrangement of the laboratories in which the work is
performed; and (4) a close adherence to the most approved methods of
manipulation.
On the other hand, if due observance is not paid to these conditions,
the sources of error are numerous, and inaccurate results inevitable.
We will endeavor to point out in this report the best means of meeting
the proper conditions for obtaining the highest degree of accuracy
consistent with fairly rapid work. It would be manifestly impossible
to observe so great a refinement of accuracy in this work as would be
employed in exact scientific research.
This would be unnecessary for the end in view, and impossible on
account of the amount of time that would be required.