thin chips were heated in the autoclave with 1100 

 cc. of 4.5 per cent Na 2 CO 3 solution, containing 3 

 times the amount of Na 2 O theoretically necessary 

 for saponification. In J hour the temperature 

 reached 100C. and in the next 15 minutes, while 

 the pressure rose to 30 pounds, 16 cc. of turpentine 

 distilled over, equivalent to 26 gallons per cord. 

 The heating was continued for a total of 2| hours 

 up to 45 pounds pressure. The combined "turps" 

 represented a yield of 33 gallons per cord. The 

 final extract was dark brown, showing that car- 

 bonate even at low pressures has a decided action 

 on the lignin. On cooling, the soap precipitate was 

 whiter than in the case of NaOH. 



3. Vacuum Treatment 



250 grams of thin chips were heated in the 

 vacuum apparatus with 1500 cc. of 2.7 per cent 

 carbonate solution (3 times theory). As low tem- 

 peratures were ineffective, the water bath was 

 kept boiling. After an hour or more at atmospheric 

 pressure the solution was yellowish and consider- 

 able rosin was dissolved. Distillation was then 

 carried on under a vacuum of 12-15 inches and 

 water vapor and volatile oils came over at 78- 

 82C. Even after 4 hours the yield of turps only 

 represented 15 gallons per cord. The liquor gave 

 a very white precipitate of soap on cooling and the 

 solution was perfectly transparent. However, re- 

 moval of the turpentine was far from being com- 

 plete. 



In general, then, caustic soda seemed to be the 

 more effective agent for extraction. Sodium Car- 

 bonate gave lighter extracts and somewhat cleaner 

 soap precipitates, but penetration of the wood was 

 incomplete and frothing rather more pronounced. 

 Elevated temperatures and pressures facilitated the 

 removal of rosin and turpentine, but occasioned 

 greater attack of the wood itself. The size of the 

 wood units proved to be a highly important factor 

 in extraction of the oleoresin. A fine state of 

 division represented by the shavings greatly sim- 

 plified the problem of extraction. On the other 

 hand, the production of good paper pulp necessitates 

 the preparation of the wood in chip form. 



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