THE SUITABILITY OF AMERICAN WOODS FOR PAPER PULP 43 
By Mechanical Process 
Reduces fairly readily. 
Pulp: Slightly reddish in color, somewhat brittle. 
Power required: 50 to 60 per cent more than for white spruce, to obtain 
standard strength. 
Uses to which pulp is suited: As partial substitute for white spruce ground 
wood. 
Western Hemlock (Tsuga heterophylla) 
Other names in use. — Hemlock, western hemlock, hemlock spruce, and Alaska 
pine. In the lumber trade the wood is often called West coast and Pacific hem- 
lock. In England it is largely known as western hemlock fir and Prince Albert's 
fir. 
Range. — From southeastern Alaska to northern Idaho and northwestern 
Montana, and southward in Washington and western Oregon to northwestern 
California. The best stands are found in the coast region and through the 
Cascade Mountains at an elevation of 1,500 to 3,500 feet. 
Oven-dry weight per cubic foot, green volume. — 23 pounds. 
Fiber length. — 2.7 mm. 
By Sulphite Process 
Reduces readily, more like spruce than eastern hemlock. 
Unbleached pulp: Tough and strong; much lighter in color and finer in texture 
than eastern hemlock. 
Yield : 45 to 50 per cent. 
Bleach required: 15 to 25 per cent. 
Uses to which pulp is suited: News, wrapping, book, and high-grade printing 
papers. 
By Sulphate Process 
Reduces readily. 
Unbleached pulp: Very strong and tough. 
Yields 45 to 50 per cent of strong pulp. 
Bleaching properties probably similar to those of eastern hemlock. 
Uses to which pulp is suited: High-grade kraft wrapping papers and fiber 
board. 
By Mechanical Process 
Reduces readily. 
Pulp: Of excellent color and standard strength. 
Power required: 10 to 15 per cent more than for spruce. 
Uses to which pulp is suited : Practically all uses requiring ground wood. 
Tamarack (Larix laricina formerly L. americana) 
Other names in use. — Larch, hackmatack, and American larch. 
Range. — From Newfoundland and Labrador northward, through the Hudson 
Bay region, to the Mackenzie River and reappearing in Alaska between Cook 
Inlet and the Yukon River; southward in the East to northern and eastern 
Pennsylvania, western Maryland, northeastern West Virginia, northern Ohio, 
Indiana, and Illinois, and northeastern Minnesota; in western Canada extending 
southward along the eastern base of the Rockies. 
Oven-dry weight per cubic foot, green volume. — 31 pounds. 
Fiber length. — 2.6 mm. 
By Sulphite Process 
Reduces with difficulty. 
Unbleached pulp: Brash, shivy, and dark in color; fairly easily bleached to 
satisfactory product. 
Yields: 40 to 45 per cent. 
Bleach required: 15 to 25 per cent. 
Uses to which pulp is suited: Low-grade wrapping papers. 
By Sulphate Process 
Reduces readily. 
Unbleached pulp: Very strong and tough. 
Yields: 45 to 50 per cent of strong pulp, 35 to 40 per cent of pulp for bleaching. 
Bleach required: 25 to 30 per cent. 
Uses to which pulp is suited: High-grade kraft wrapping papers and fiber 
board. 
