EXPERIMENTAL WORK. 13 



ments. Close observation of the accumulation of the oils indicates 

 that these variations were not sufficient to cause a material difference 

 in the amounts of oil recovered. 



In the experiments with fresh chips in the first relieving or the first 

 stage of the distillation it required approximately 14 parts of water to 

 remove 1 part of oil from the fine chips, 13 parts to remove 1 part 

 from the medium chips, and 30 parts to remove 1 part from the 

 coarse chips. The proportion of oils to condensed water decreased 

 very rapidly and in the fourth or next to the last stage it required 

 approximately 500 parts of water to remove 1 part of turpentine 

 from the fine chips, approximately 350 parts to remove 1 part from 

 the medium, and approximately 900 parts to remove 1 part from the 

 coarse chips. Considering the whole distillation (four relievings) 1 

 part of oils was removed from the fine chips by approximately 51 

 parts gf water, from the medium by 47 parts, and from the coarse by 

 90 parts. From the steamed chips 55 to 200 parts of water on the 

 fine, 90 on the medium, and 125 on the coarse were required to 

 remove 1 part of turpentine in the first stage, and from 500 to 1,000 

 parts were required in the final stage by chips of all sizes. Of the total 

 oils recovered, 1 part required from 133 to 310 parts of water, the 

 greatest proportion being required by the coarse chips. 



It will also be seen from Table 1 that from chips which would pass 

 an inch screen more than 90 per cent of the recovered turpentine was 

 removed in two relievings and that the total time of steaming to 

 accomplish this was from 1 to 1| hours. In Cook 7, chips small 

 enough to pass a one-fourth inch screen required 1,370 cc of water to 

 remove 57 cc of turpentine from 2,500 grams of chips; that is, 94 per 

 cent of the turpentine was recovered by an average of 1 pound of 

 steam to 1.8 pounds of wood. In Cook 6, on chips passing an inch 

 screen, but not the one-fourth inch screen, 1,700 cc of water removed 

 69 cc or 93 per cent of the recovered turpentine from 2,500 grams of 

 chips, or an average of 1 pound of steam to 1.3 pounds of chips. In 

 Cook 8, where the chips would not pass an inch screen, 1,780 cc of 

 water removed 34 cc or 76 per cent, of the recovered turpentine from 

 2,000 grams of wood, or an average of 1 pound of steam to 1.1 parts of 

 wood. It will also be observed (p. 12) that 6 cc or 8 per cent, of the 

 recovered turpentine was recovered in Cook 8 in the subsequent pulp 

 cook, where the digester was closed for 1 hour at a pressure of 75 

 pounds (160 C.). This turpentine was removed by 600 cc of water 

 in 25 minutes' relieving. 



In these experiments the purpose was to remove all wood turpentine 

 and pine oil from the chips, and not to determine the best conditions 

 for doing this. Steaming was continued until the proportion of tur- 

 pentine to condensed steam or water was much smaller than is usual 

 or would be profitable on a commercial scale. Apparently all light 



