5l8 FULLING 



heterophylla, western hemlock 

 mertensiana, mountain hemlock 



Of these Canadian imports, spruce and balsam fir predominated in the East 

 and Lake States ; hemlock, Douglas fir and true firs in the Pacific Northwest. 



Of the domestic pulpwood, three-fifths were cut in the South. About 90 

 per cent of this southern pulpwood was southern yellow pine, principally 

 loblolly {P. taeda). The remaining 10 per cent consisted of the following pines: 



Pinus caribaea, slash 

 clausa, sand 

 echinata, shortleaf 

 glabra, spruce 

 palustris, longleaf 

 rigida, pitch 



rigida var. serotina, pond 

 virginiana, Virginia 



Hardwoods have always been secondary sources of pulpwood. Among other 

 reasons is the shortness of their fibers as compared with those of conifers 

 (1 mm. vs. 3 mm.). Furthermore, the three standard methods of pulping yield 

 less than 50 per cent of the original wood by weight, which is true also of 

 softwoods by the sulfite and soda methods. Such return is too low to com- 

 pensate for inferior quality in hardwood pulp. A remedy for this is offered 

 by the so-called semi-chemical process of pulping, which yields about 20 per 

 cent better return than the conventional chemical methods and thus promises 

 possibly greater pulp utilization of low-grade hardwoods. 



The hardwoods, which made up 15 per cent of the pulpwood in 1954, con- 

 sisted principally of aspens and gums. More specifically they were: 



Acer rubrum, red maple 



saccharum, sugar maple 



saccharinum, silver maple 

 Aesculus octandra, buckeye 

 Ailanthns glandulosa, ailanthus 

 Alnus rubra, red alder 

 Betula lutea, yellow birch 



papyrifera, paper birch 

 Castanea dentata, chestnut 

 Fagus grandijolia, beech 

 Fraxinus americanu, ash 

 Liquidambar styraciflua, sweet gum 

 Liriodendron tulipijera, yellow poplar 

 Magnolia acuminata, cucumber 



