SUITABILITY OF LONGLEAF PIKE FOR PAPER PULP. 7 
in ten-thousandths of an inch, and also as a "strength factor/ 7 which 
is the average of the five pop tests divided by the weight per ream 
of 500 sheets of paper, each measuring 24 by 36 inches. The relative 
resistance of the papers to wear was determined by crumpling the 
sheets in the hand, and all other properties mentioned, except 
strength, were determined by feel or by observation without the aid 
of instruments. 
DEFINITIONS OF TERMS USED. 
While the significance of most of the terms used in recording the 
test data (Tables 1 to 10, inclusive) is either self-evident or sufficiently 
clear in view of the previous discussion, there are several which may 
require explanation. 
Water in chips. — The amount of moisture is expressed in per- 
centage of water, based on the calculated bone-dry weight of the 
chips. 
All sodium compounds as Na 2 0. — This is the sum of the sodium 
oxide (Na 2 0) equivalents of the amounts of the several constituents 
entering into the chemical charge. "Total Na 2 0" has an analagous 
significance in the soda process. 
SulpJiidity. — The sulphidity of the liquor charge is the percentage 
ratio of the Na 2 equivalent of the amount of sodium sulphide 
(Na 2 S) used to the amount of all sodium compounds present expressed 
as Na 2 0. 
Causticity. — This has a similar significance with respect to the 
amount of caustic soda (NaOH) used. 
Initial volume of digester liquors. — The digester liquors include the 
water in the liquor charge, together with the water in the chips and 
the water condensed from the steam passed into the digester during 
cooking. This condensation, of course, does not enter into the calcu- 
lation of the initial volume. 
Apparent condensation. — The apparent condensation is the differ- 
ence between the calculated initial volume of the digester liquors and 
the observed volume, as read from a water gauge, at the end of the 
cook. It roughly represents the amount of steam condensing in the 
digester during cooking, but does not take into account the volume 
of the pulp and the differences in temperature of the initial and final 
liquors, nor the steam and liquid lost during relief. 
SEMICOMMERCIAL TESTS. 
SULPHATE PROCESS. 
The object of the semicommercial sulphate cooks was to secure the 
best quality of pulp with the highest possible yield. The severity of 
cooking employed depends largely upon the use for which the pulps 
are intended. If bleaching or easy bleaching pulps, such as are used 
in book and other white papers, are desired, more severe cooking 
