SUITABILITY OF LONGLEAF PINE FOR PAPER PULP. 9 



TABLE 1. Record of semicommerdal tests using the sulphate process Continued. 



(P. L. 138, S. L. 176.) 

 1 A portion of the digester liquor was lost, due to leaks during the early stages of cooking. 



SEVERE COOKING TREATMENTS. 



The effect of more severe cooking treatments, produced mainly 

 by greater initial concentrations and amounts of active cooking 

 chemicals, was evidenced by the thoroughly cooked or overcooked 

 pulps from cooks 77 and 141 (Table 1). The crude pulps were not 

 only free from chips and shives, but also seemed to be soft and 

 fluffy. The papers made from the beaten pulps, however, were of 

 very superior quality with regard to resistance to wear, toughness, 

 and strength, the strength factors being 0.91 and 0.86 for cooks 77 

 and 141, respectively. Both pulps became slightly hydrated during 

 the beater treatments, which produced a parchment izing effect and 

 increased the strength and toughness. Either of the papers could be 

 24542 14 2 



