PRODUCTION OF SULPHITE PULP FROM SPRUCE. 3 
many other woods will be used, as spruce is becoming too expen- 
sive. The sulphite process can not be used on woods that contain 
much pitch, because a large part of the pitch remains in the pulp 
and later causes much trouble on the wires of the paper machine. 
This problem has been the subject of much study and investigation 
but no successful method has yet been found for cooking such wood 
by this process and eliminating the resin. 
The curves in figure 1 show the per cent of the principal woods used 
in the sulphite process from the year 1900 to 1911. The consump- 
tion of spruce is decreasing, and other woods are being used more 
PERCENT: 
YEAR 
Fic. 1.—Consumption of wood by the sulphite process in the United States 1900-1911. 
extensively than before. Table 2 gives in detail the kind and amount 
of each wood used. ; 
TABLE 2.—Consumption.of wood by the sulphite process in the United States. 
[From Census and Forest Service Reports.] 
1900 1905 1906 1907 
Kind of wood. e é _ * 
er er er er 
Cords. ent Cords. cone Cords. ae Cords. cont 
Sprites eater h ee secs. 790,153 | 83.9} 1,176,930 | 72.2| 1,374,212] 70.2) 1,422,400] 69.1 
Hionilockem re eer ele Selec cacscce 344,579 | 21.1 516, 512 | 26.4 541,113 | 26.2 
IPO DIBITS (coe cdadognaeuase eed lonBeosecueed aueasel PaaS eeeoesen |beseee aueooucepeaciacasce 1, 536 sil 
Baleaniie tener ere hot | A occ le ise 45,943 | 2.8 22,314] 1.1 28,356| 1.4 
TPAD. Secs | ee P 18,606} 1.1 3,600} .2 3, 200 a 
