high pressure for 4 hours gave a soft pulp, the yield 

 being 22.5 per cent of the original wood and 41.5 

 per cent of the actual wood contained therein. 



In Experiment 3 the proportion of caustic soda 

 was raised to a little over twice the theoretical 

 amount for saponification and distillation of the 

 turpentine was carried on for 4 hours at 25-30 

 pounds pressure. Disintegration of the rosin was 

 sufficiently thorough to allow a high recovery of 

 turpentine (44.6 gals, per cord), but an appreciable 

 amount of rosin (7.8 %) remained unsaponified. 

 Analysis of the liquor after extraction showed an 

 absence of excess caustic, indicating that the proper 

 alkali ratio had not yet been reached. The weight 

 of the extracted chips was found to be 44.8 per 

 cent of the original resinous wood, so that the 

 decomposition of the lignin and other non-resinous 

 constituents of the wood had amounted to 9.5 per 

 cent of the original wood or 17.5 per cent of the 

 " actual wood". In this experiment for the first 

 time careful attention was paid to the distribution 

 of the rosin. The direct extract contained 66.2 per 

 cent of the true rosin content in the form of rosin 

 soap. By direct cooling only 72.7 per cent of 

 this soap was precipitated, due to the marked 

 solubility in the faintly alkaline solution. On 

 strengthening the liquor to 8 per cent NaOH, 

 however, 96 per cent of the soap was deposited, 

 representing 63.5 per cent of the total rosin in the 

 wood. The first wash liquor contained 11.7 per 

 cent of the total rosin and the second wash liquor 

 an additional 2.9 per cent. The chips retained 

 7.8 per cent of the rosin in the free state and about 

 3 per cent more in the form of soap which had 

 escaped the first two washings. A small amount 

 of soap was found in the aqueous distillate, while 

 the balance (about 7 per cent) represented de- 

 composition by the alkali and slight mechanical 

 losses. Final steaming of the chips in 5.4 per 

 cent NaOH for 3J hours yielded 41 per cent of 

 soft, thoroughly disintegrated pulp. 



To determine the effect of stronger caustic soda, 

 n ratio of 4.34 was used in Experiment 4. Extrac- 

 tion of rosin was in this case complete and the 



33 



