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BULLETIN 1485, U. S. DEPARTMENT OF AGRICULTURE 
not make paper of quite as great strength. The unbleached pulp is 
darker and requires more bleach. Western hemlock is much more 
easily pulped than eastern hemlock, and the pulp more nearly 
resembles that from spruce. Western hemlock is used to a certain 
extent in the manufacture of mechanical pulp, but the power require- 
ments to produce pulp of the same strength as spruce are somewhat 
greater; or, if pulp is produced with the same power consumption, 
a weaker pulp requiring more sulphite in the manufacture of standard 
newsprint is obtained. 
The firs can be used in all the processes. They produce pulp very 
similar to that from spruce in practically every characteristic. With 
Fig. 
-Beater of semicommercial type used in the pulping experiments 
red fir, however, both the sulphite and mechanical pulps are darker 
colored, and the sulphite is more difficult to bleach. 
As to the pines, general statements can not be made with the same 
assurance. Lodgepole pine and western yellow pine have been used 
successfully in extensive experiments in the manufacture of mechan- 
ical pulp, the color of which was satisfactory and the strength, power 
consumption considered, closely comparable to that of spruce. 
Under the sulphite process, jack pine, loblolly pine, lodgepole pine, 
Norway pine, pond pine, sand pine, and Virginia pine yielded pulp 
of very fair quality, capable of bleaching with reasonable quantities 
of chemical. In the case of loblolly pine, lodgepole pine, Norway 
pine, sand pine, and Virginia pine the uniformity of the digestion 
