FOBEST SERVICE. 545 



The treating plant of the Oregon Agricultural College was oper- 

 ated by a service representative for a week during a special short 

 course, and the service assisted in the installation of a small open- 

 tank plant for the University of Colorado. 



WOOD DISTILLATION. 



The results of studies dealing with the analysis, refining, and com- 

 position of wood turpentines, concluded during the year, may be 

 summarized briefly as: (1) A new distillation method by which more 

 complete and accurate conclusions in regard to the composition of a 

 turpentine can be drawn than is possible with fonner methods of 

 equal simplicity; (2) refining of five samples of crude wood turpen- 

 tines produced by different commercial processes, and the description 

 of methods of refining applicable to wood turpentines of a wide range 

 in composition; (3) data which show how the composition of wood 

 turpentines is influenced by different methods of production, by re- 

 fining, by storage, and how wood turpentines compare with gum 

 turpentines in composition; and (4) the presentation in specific form 

 for the first time of the differences in composition between gum and 

 wood turpentines, and between different samples of wood turpentines, 

 and the reasons therefor. 



Experiments on the steam extraction of volatile oils from resinous 

 woods were completed. The effect of size of chip, steam pressure, 

 and speed of distillation on the yield of oil and efficiency of the 

 process were determined. With a knowledge of the various factors 

 of cost at any steam distillation plant it will be possible from the 

 results of the experiments to decide readily on the most economical 

 conditions for conducting distillation. 



Attempts to distill commercially resinous woods of the Xorthwest, 

 particularly Douglas fir, have not proved entirely successful. At the 

 beginning of the year the Forest Service entered into an agreement 

 with the University of Washington by which cooperative experi- 

 ments will be carried on to determine the best methods of distillation 

 and refining, the distillation methods applicable to Douglas fir and 

 other woods of the Northwest, the yield of distillates from the 

 various species, and the possibilities of their commercial use. Some 

 work has already been done, but no definite results have as yet been 

 secured. 



The hardwood distillation industry has operated upon beech, birch, 

 and maple almost exclusively. Experiments were undertaken to de- 

 termine the comparative yield of valuable products of a number of 

 other species. As compared with average yields per cord of 8.6, 11.4, 

 and 11.7 gallons of wood alcohol, respectively, for birch, beech, and 

 maple, chestnut yielded 3.6, red gum 9.2, oak 9.2, and hickory 15.3 

 gallons. In acetate of lime, as compared with average yields per 

 cord of 349, 318, and 202 pounds, respectively, for birch, beech, and 

 maple, chestnut yielded 195, red gum 258, oak 300, and hickory 338 

 pounds. 



Because it seemed probable that a larger yield of valuable distilla- 

 tion products than is now obtained by commercial plants could be 

 secured, a study of methods of distillation has been planned. Very 

 little experimental work has as yet been done, though incidentally, 

 in the determinations of yields from various species, the yield of 



70481°— AGB 1912 35 



