recovery of the turpentine was accomplished more 

 quickly. A large excess of NaOH remained after 

 extraction and this experiment probably represents 

 the upper limit as far as ratio of alkali to wood is con- 

 cerned. The direct extract contained 77.2 per cent of 

 the total rosin, 97 per cent of which was precipitat- 

 ed as soap on addition of excess caustic soda. 

 Only 0.15 per cent of the rosin content of the wood 

 remained unsaponified in the chips. The stronger 

 caustic occasioned solution of 24.1 per cent of the 

 actual wood content. The second stage of the 

 process gave a yield of 41.8 per cent pulp, the fibre 

 being softer than desired. 



Experiment 5 is undoubtedly the most typical 

 of the series. A lower ratio of Na 2 O (3.47) was 

 found to be entirely satisfactory. The main ex- 

 traction was carried on at the lower pressure of 

 15 pounds and an examination of the turpentine 

 curve in Figure 2 will show that higher pressures 

 are apparently not necessary in obtaining rapid 

 distillation of the volatile oils. The time under 

 pressure was purposely lengthened to 4 hours and 

 the pressure finally raised to 20 pounds to ensure a 

 maximum yield of turpentine. The percentage 

 calculated from this run has been chosen as repre- 

 senting the true " turpentine" content of the wood. 

 Extraction of rosin was practically complete and 

 considerable excess of caustic was present in the 

 liquors. The direct extract contained 74.5 per 

 cent of the total rosin and the first wash liquor 

 an additional 11.2 per cent. 



Special attention is called to the fact that in 

 this experiment the chips were finally cooked 

 according to the procedure suggested for industrial 

 application. The main portion of the direct ex- 

 tract was strengthened with a calculated amount of 

 caustic soda to precipitate the rosin soap more 

 completely. The black supernatant liquor was then 

 used for the soda cook. The pulp so obtained was 

 in no way inferior to the fibres from the other 

 runs. The yield was 46.4 per cent of the actual 

 wood. The pulp retained the general chip form, 

 but was easily disintegrated by hand and after 

 beating was readily made up into uniform sheets 

 of favorable strength and color. 



34 



