THE SUITABILITY OF AMERICAN WOODS FOR PAPER PULP 59 
By Soda Process 
Reduces readily. 
Unbleached pulp: Rather difficult to bleach; differs from soda pulps of most 
other species on account of being noticeably less opaque. 
Yields: 35 to 40 per cent. 
Bleached required: 20 to 30 per cent. 
By Mechanical Process 
Not determined. 
Sassafras (Sassafras variifolium, formerly S. sassafras) 
Other names in use. — Sassafras is the universal name for this species. 
Range. — From southern Maine and eastern Massachusetts through southern 
Vermont, southern Ontario, and central Michigan, southeastern Iowa to eastern 
Kansas, Arkansas, and Oklahoma; south to central Florida, and eastern Texas. 
Oven-dry weight per cubic foot, green volume. — 26 pounds. 
Fiber length. — 0.9 mm. 
By Sulphite Process 
Not sucessfully reduced. 
By Soda Process 
Reduces readily. 
L T nbleached pulp: Very difficult to bleach except where yields are too low 
for commercial consideration. 
Yields: 30 to 35 per cent. 
Bleach required: 30 to 35 per cent. 
By Mechanical Process 
Not determined. 
Rock Elm (Ulmus racemosa) 
Other names in use. — Cork elm and hickory elm. Rock elm is the usual 
name applied to the lumber. 
Range. — From Quebec (eastern townships) through Ontario, and south through 
northwestern New Hampshire to southern Vermont, and to northern New Jersey; 
westward through northern New York, southern Michigan, and central Wis- 
consin; southwestern Minnesota to northeastern Nebraska, western Missouri, 
eastern Kansas, and middle Tennessee. 
Oven-dry weight per cubic foot, green volume. — 36 pounds. 
Fiber length. — 1.3 mm. 
By Sulphite Process 
Reduces readily. 
Unbleached pulp: Of poor color; easily bleached. 
Yields: 45 to 50 per cent. 
Bleach required: 10 to 15 per cent. 
By Soda Process 
Reduces readily. 
Unbleached pulp: Fairly easy to bleach. 
Yields: 45 to 50 per cent. 
Bleach required: 20 to 25 per cent. 
By Mechanical Process 
Not determined. 
Slippery Elm (Ulmus fuiva, formerly U. pubescens) 
Other names in use. — This species is also commonly known as red elm and 
moose elm. The lumber is often sold as "gray elm." 
Range. — From the lower St. Lawrence River through Ontario to South Dakota 
and eastern Nebraska, southeastern Kansas, southwestern Arkansas, and Okla- 
homa; south to western Florida, central Alabama, and Mississippi, western 
Louisiana, and central Texas. 
Oven-dry weight per cubic foot, green volume. — 30 pounds. 
Fiber length. — 1.7 mm. 
