THE SUITABILITY OF AMERICAN WOODS FOR PAPER PULP 13 
into tank X from which it was originally obtained, steam being 
admitted to. the digester above it to supply the force necessary. 
By weighing and analyzing the liquor before impregnation and during 
its return the quantity of chemical remaining in the digester could 
be determined and controlled. After sufficient liquor had been 
returned to the tank to leave the desired quantity in the digester, 
the connections referred to were closed, water was added if necessary 
Digester used for sulphite cooks since 1916 (side elevation) 
to give the desired volume in the digester, and the cook was carried 
on in the usual manner. The usual procedure applied also to screen- 
and other treatments. 3 
After the pulp was completely washed and drained it was hydrau- 
lic ally pressed, opened up in a swing-hammer shredder, "and weighed 
and sampled for moisture. From the moisture determination the 
3 Kress, Otto, Wells, Sidney D., and Edwardes, Vance P. names first the equipment and 
OPERATION OF AN EXPERIMENTAL LABORATORY. Paper, April 19, 1920. 
