Experiment 6 represents a run on smaller chips 

 to ascertain the differences in alkali penetration. 

 A batch of larger chips from the main supply was 

 reduced by splitting to an average size of about 

 1J in. x J-f in. x Vie in. These chips were about 

 half the thickness of those in the other seven ex- 

 periments and might be difficult to obtain on an 

 industrial scale without sacrificing uniformity. How- 

 ever, it would be entirely practicable to use chips 

 smaller than those of the main supply and Experi- 

 ment 6 indicates the general variations with the finer 

 material. 



The wood was treated practically the same as 

 in the preceding experiment. The amount of 

 caustic soda was reduced to 3 times that theoreti- 

 cally necessary for saponification and distillation 

 was carried on at the lowest feasible pressure 

 (15-20 pounds). It was found that the last port- 

 tions of turpentine were removed more readily 

 than with larger chips and the time of preliminary 

 treatment was materially shortened, due to the 

 more rapid penetration of the alkali to the interior 

 of the chips. There was no appreciable difference 

 in extent of lignin decomposition, the loss in weight 

 sustained by the "actual wood" (23.2 per cent) 

 being even less than in Experiment 5 (24.8 per 

 cent) by reason of the shorter steaming period. 

 The soda cook gave a high yield of pulp (47.7 per 

 cent) and the pulp was of excellent quality. 

 Preserving the full length of the chips on reduction 

 of the wood for this experiment no doubt obviated 

 the tendency toward short, uneven fibre from very 

 small chips. 



In Experiment 7 an attempt was made to ex- 

 tract the oleoresin by means of sodium carbonate. 

 An ample excess of carbonate was used (3.26 times 

 the saponification value) and the preliminary treat- 

 ment was executed in a manner which the experi- 

 ence with caustic soda suggested as most favorable 

 to extraction. It was found that penetration of 

 the wood was slow and that solution of the rosin 

 was far from being complete in the reasonably 

 long period allowed for heating. Furthermore, 

 frothing was more troublesome than with caustic 



35 



