32 BULLETIN 316, U. S. DEPARTMENT OF AGRICULTURE. 
to a mill with, great economy. The willow could be mixed with long- 
leaf pine, which has very long fibers and which is coming into use in 
the South for pulp. 
Should willow become important in that region for pulp, black 
willow on the Mississippi bottoms offers ideal conditions for prac- 
ticing forest management. The tree grows rapidly in dense natural 
stands and reproduces abundantly by seed or sprouts. The bottom 
lands are low priced and highly fertile, the growing season is long, 
transportation is cheap, and logging conditions excellent. 
ARTIFICIAL LIMBS. 
It is estimated that there are now in this country nearly 200 manu- 
facturers of artificial limbs. The first artificial leg, other than the 
ordinary wooden pegs, is said to have been made in London by a 
man named Cork in the early part of the nineteenth century. 
Although very imperfect, this device was a great improvement over 
the old peg. The early name of "cork legs" was continued, and in 
time the public began to think that these legs were made of cork. 
The materials most commonly used are wood, leather, aluminum, 
fiber, or papier-mache for the major parts and rubber and felt for 
the minor parts. The majority of manufacturers use some wood, 
usually willow. Of the species used the following are most common: 
White, yellow, crack, black, and peachleaf willows. In New York 
the yellow willow is the most commonly used, although both the white 
and crack willow are used occasionally. In the Lake States the white 
and crack willows are used the most, and are about equal in impor- 
tance. The consumption of willow wood for this purpose offers to 
the enterprising farmer situated near a city a means of selling a por- 
tion of good willow trees at a fair price. 
TRADE NAMES FOR SPECIES USED BY MANUFACTURERS. 
The name " white willow" is usually applied to the sapwood of 
any willow and does not in the trade necessarily indicate the regular 
white willow, although it may. In Minnesota the crack willow is 
called white willow, as is also Salix amygdaloides, a common wild 
willow of that region, which is, however, seldom used. The wood 
called " white willow" in Minnesota is tough, full of knots, and hard 
to work. The wild willow, when it is used, generally goes into some 
part that does not come in contact with the body. It is considered 
heavier, more porous, and stronger than the wood called "red wil- 
low." The white willow of Missouri is Salix amygdaloides and is also 
known to the trade as swamp willow. The so-called imported 
English willow is all grown in the United States, but is doubtless 
from the species Salix alba, which is the English white willow. The 
Pennsylvania red willow of the trade is also Salix alba, and in this 
region the wood seems to be more reddish than farther west. 
