THE SUITABILITY OF AMERICAN WOODS FOR PAPER PULP 49 
By Sulphite Process 
Pulping properties probably similar to those of aspen, but pulp less contamin- 
ated with black specks. 
By Soda Process 8 
Reduces readily. 
Unbleached pulp: Fibers longer than those from aspen; fairly easily bleached. 
Yields: 45 to 50 per cent. 
Bleach required: 15 to 20 per cent. 
By Mechanical Process 
Behavior similar to that of aspen. 
Largetooth Aspen (Populus grandidentata) 
Other names in use. — Poplar, largetoothed poplar, large poplar, white poplar, 
popple, and large American aspen, i 
Range. — Nova Scotia, New Brunswick, southern Quebec, and Ontario to 
northern Minnesota, and northeastern North Dakota; southward to Pennsyl- 
vania, Ohio, and Iowa, and along the Alleghany Mountains to North Carolina, 
central Kentucky and Tennessee. 
Oven-dry weight per cubic foot, green volume.— 22 pounds. 
Fiber length. — 1.1 mm. 
By Sulphite Process 
Reduces readily. 
Unbleached pulp: Of excellent color; bleaches fairly readily. 
Yields: 45 to 50 per cent. 
Bleach required: 15 to 20 per cent. 
By Soda Process 
Reduces readily. 
Unbleached pulp: Bleaches fairly readily. 
Yields: 40 to 45 per cent. 
Bleach required: 15 to 20 per cent. 
By Mechanical Process 
Behavior probably similar to that of aspen. 
Yellow Poplar (Liriodendron tulipifera) 
Other names in use. — Tulip poplar, tulip-tree, whitewood, poplar, white poplar, 
blue poplar, and hickory poplar. 
Range. — From Rhode Island to southwestern Vermont and west to Lake 
Michigan; south to northern Florida, southern Alabama and Mississippi; west 
of Mississippi River in northeastern Louisiana, southeastern Missouri, and 
northeastern Arkansas. 
Oven-dry weight per cubic foot, green volume. — 26 pounds. 
Fiber length. — 1.8 mm. 
By Sulphite Process 
Reduces readily. 
Unbleached pulp: Of poor color, though less contaminated with black specks 
than is aspen sulphite; difficult to bleach. 
Yields: 45 to 50 per cent. 
Bleach required: 20 to 25 per cent. 
By Soda Process 
Reduces fairly readily. 
Unbleached pulp: Stronger than aspen pulp; fairly easily bleached. 
Yields: 40 to 45 per cent. 
Bleach required: 15 to 20 per cent. 9 
8 Tests were also made on Norway poplar (Populus canadensis eugenei, a hybrid) which behaves like Cot- 
tonwood. Norway poplar is believed to be a cross between P. deltoides and P. nigra italica — a European 
species — and the resultant hybrid has been planted extensively in this country. 
6 About 12 to 18 per cent when cooked by sulphate process to yields indicated. 
31897°— 27 4 
