EXPERIMENTAL WORK. 9 



after separating from the water. The volume of water condensed 

 was also noted. After the turpentine had ceased to distill in meas- 

 urable quantities the wood was cooked at different temperatures for 

 various periods of time. The chips as received from the chipper were 

 very irregular in size and shape, varying from coarse dust to pieces 

 an inch thick and several inches long. They were screened into three 

 sizes those smaller than J inch mesh, 31 per cent; those J to 1 inch 

 mesh, 44 per cent ; and those larger than 1 inch mesh, 25 per cent of 

 the wood. This separation was made in order to obtain data on the 

 quantity of the various products that could be obtained from each 

 of the several sizes and the time required to steam off the turpentine 

 and to cook properly the chips of different sizes. 



All the steaming data are found in Table 1. These include the 

 amount o^ air-dry and moisture-free wood employed in each experi- 

 ment; the volume of dilute alkali solution added; the volume of 

 water and of turpentine and also the percentage of the total turpen- 

 tine and the time and pressure each time the digester was relieved; 

 the total volume of water and turpentine recovered in relieving and 

 the actual time of relieving; the percentage of crude turpentine on 

 the basis of the moisture-free wood; the yield of crude turpentine 

 estimated to a cord of 4,000 pounds of air-dry wood assumed to 

 contain 20 per cent of moisture; and the specific gravity and refrac- 

 tive index at 20 C. of the crude turpentine. These data are given 

 on the screened fresh and steamed chips and also on the unscreened 

 steamed chips. 



