THE SUITABILITY OF AMERICAN WOODS FOR PAPER PULP 15 
the weight of the pulp, according to requirements estimated from 
preliminary observations. Forty grams of pulp in 1,600 cubic 
centimeters of total liquid were used in each test. The mixture 
End Elevation 
*UA 
J 
Fig. 6.— Digester used for alkaline cooks since 1916 (end elevation) 
was kept in constant agitation at a temperature of between 100° 
and 110° F. until the bleach was exhausted. Hand sheets were 
made of the pulp, and the measure of bleaching was taken as the 
quantity of bleach beyond which no improvement in color was 
observable. 
