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 



































































































eo 































































































































«o 























































SPRUC 



I 







































































40 























































































































































HEMLO 



:k 































































MILL W 



ftSTE 































































WHITE 



FIR 







Fig. 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. 



Cords. 



Per 

 cent. 



Cords. 



Per 

 cent. 



Cords. 



Per 



cent. 



Cords. 



Per 

 cent. 





790, 153 



83.9 



1,176,930 

 344, 579 



72.2 

 21.1 



1,374,212 

 516, 512 



70.2 

 26.4 



1,422,400 



541,113 



1,536 



28,356 



3,200 



69.1 





26.2 









.1 









45,943 

 18, 606 



2.8 

 1.1 



22, 314 

 3,600 



1.1 

 .2 



1.4 









.2 



White fir 









Slab wood and other mill 





















152,364 



16.1 



44,341 



2.8 



41, 981 



2.1 



62, 890 



3.0 







Total 



942,517 





1, 630, 393 





1,958,619 



2 059 495 













