2 BULLETIN 404, U. S. DEPARTMENT OF AGRICULTURE. 
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 sec- 
tions 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 elon- 
gated 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 cent of the 
weight of the hurds consists of hemp fiber, in strands from 3 inches 
to 8 feet in length. Some fragments of the bark, made up of short 
cubical cells, usually dark in color, cling to the strands of fiber. 
CHARACTER OF HURDS AFFECTED BY RETTING. 
Nearly all of the hemp in the United States is dew retted. The 
stalks are spread on the ground in swaths, as grain is laid by the cradle. 
The action of the weather, dew, and rain, aided by bacteria, dissolves 
and washes out the green coloring matter (chlorophyll) and most of 
the gums, leaving only the fibrous bark and the wood. The plants in 
this process lose about 60 per cent of their green weight, or about 40 
per cent of their air-dry weight. 
The stalks are sometimes set up in shocks to cure before retting, 
and after retting they are set up in shocks to dry. Each time the 
stalks are handled they are chucked down on the ground to keep the 
butts even. In these operations sand and clay are often driven up 
into the hollow at the base of the stalks, and this dirt, which often 
clings tenaciously, may constitute an objectionable feature in the use 
of hemp hurds for paper stock. 
In Italy and in most localities in Russia and Austria-Hungary 
where hemp is extensively cultivated, it is retted in water, but water 
retting has never been practiced in the United States except to a 
limited extent before the middle of the last century. Hurds from 
