is used in digesting the fibrous material at high 

 steam pressure for pulp. 



Where curpentine is the only product desired, 

 alkali has in some cases been added primarily to 

 disintegrate the rosin and thereby permit a more 

 nearly complete distillation of the volatile oils 

 (Hough, U. S. Pat. 903,471). 



Kerr (U. S. Pat. 832,863) has suggested a con- 

 tinuous process for the removal of turpentine and 

 rosin from wood, the turpentine being first distilled 

 with steam and the rosin being subsequently dis- 

 solved in alkaline liquor. 



I. Preliminary Experiments 



From a shipment of assorted pine waste, the 

 "box-face slab" material was selected as being 

 best suited to a laboratory investigation. This 

 wood was sound and clean, and very rich and uni- 

 form in oleoresin content. When reduced to chips 

 or shavings the wood had a strong turpentine odor 

 and burned freely with a characteristic, smoky 

 flame. Box-face slabs constitute a comparatively 

 expensive and restricted source of raw material 

 for commercial supply and the oleoresin content 

 (30-40 per cent) is higher than that of average 

 lightwood (15-25 per cent). This material, then, 

 should present perhaps the severest conditions for 

 complete extraction of rosin and turpentine, but 

 the yields must be considered a maximum for 

 southern pine waste. 



A series of experiments' was first made to deter- 

 mine the behaviour of the wood with alkalis under 

 various conditions of temperature and pressure. 

 Sample slabs were carefully cleaned by the removal 

 of bark, rosin "scrape" and other surface material. 

 Only the clean, inside wood was used in the investi- 

 gations. Some of the wood was reduced to large 

 chips about 1 in. x fin. x Jin., some to small 

 chips about ^in. x Jin. x ^V in. and another 

 portion to thin shavings. 



The action of volatile solvents was of course 

 rapid and simple. Shavings and small chips were 

 readily freed from rosin and turpentine by extrac- 

 tion in a Soxhlet, leaving the wood clean and de- 



15 



