16
Comparison of the tests and commercial practice 21
Physical tests of the papers produced 24
Conclusions 25

In preparing the report on the manufacture of paper from hemp hurds it
became evident that a short discussion of the agricultural aspects of
this material should be included in the publication. Such an article was
prepared, therefore, and the two reports are here presented together.

[NOTE.--This bulletin should be useful to all persons who are interested
in the economic phases of paper making, especially to print and book
paper manufacturers. It also should be of interest to scientific
investigators and chemists.]

=THE PRODUCTION AND HANDLING OF HEMP HURDS.=

By LYSTER H. DEWEY, _Botanist in Charge of Fiber-Plant Investigations_.

=WHAT HEMP HURDS ARE.=

The woody inner portion of the hemp stalk, broken into pieces and
separated from the fiber in the processes of breaking and scutching, is
called hemp hurds. These hurds correspond to shives in flax, but are
much coarser and are usually softer in texture.

The hemp stalk grown in a broadcast crop for fiber production is from
one-eighth to three-eighths of an inch in diameter and from 4 to 10 feet
tall. The stalk is hollow, with a cylindrical woody shell, thick near
the base, where the stalk is nearly solid, and thinner above, where the
hollow is relatively wider.

In the process of breaking, the woody cylinder inside of the
fiber-bearing bark is broken into pieces one-half of an inch to 3 inches
long and usually split into numerous segments. The thicker lower
sections are split less than the thin-shelled upper ones, and they are
often left quite solid.

=PITH, WOOD, AND FIBER.=

The inner surface of the hurds usually bears a layer of pith, consisting
of thin-walled cells nearly spherical or angular, but not elongated.
They are more or less crushed and torn. They are probably of little
value for paper, but they constitute less than 1 per cent of the weight
of the hurds. The principal weight and bulk consist of slender elongated
woody cells. The outer surface is covered with fine secondary fibers
composed of slender elongated cells, tougher than those of the wood but
finer and shorter than those of the hemp fiber of commerce. No method
has been devised thus far which completely separates from the hurds all
of the long fiber. From 5 to 15 per ce