150RDKRED PITS IX DOL'CLAS KIK <S1i> 



In general the results obtained showed that good penetration and 

 absorption accompanied a condition in which the majority of tlie tori 

 were found in tlie central or unaspirated condition. 



THK POSITIONS OF THE TORI IN BORDERED PITS oF DOUGLAS FIR AI-ll'R 

 THE MATERIAL WAS SUBJECTED TO VARIOUS ARTIFICIAL TREATMENTS 



Air-dry Material Treated zvith Air. — Examinations were made on 

 two specimens of mountain-grown material from Missoula County, 

 Montana. Both specimens were heartwood and were treated with air. 

 The pressure was applied to the end. or cross-section, of the block. The 

 nature of the treatment and the results of the microscopic examinations 

 of the pits after treatment are shown in Table 6. 



Practically no difiference was to be found here in the positions of the 

 tori after the treatments and the positions they occupied in normal 

 untreated air-dry wood of the same specimen, as shown in Table 2. 



Stcaiii-trcatcd Material. — Three specimens of air-dry heartwood. 

 mountain-grown material, from Missoula County. Montana, were given 

 steam treatments. The specimens, which were small blocks about 3^ by 

 ^ by ^ inch in size, were placed in a closed cylinder and steam pres- 

 sure applied. The results of the microscopic examinations made on the 

 material after treatment are given in Table 7. 



The positions of the tori were practically the same after these treat- 

 ments as the\" were in the normal untreated air-dry material of the 

 same specimen shown in Table 2. 



Alcohol-soaked, Oveii-dried Material. — A piece about 1/2 by y^ by i 

 inch in size of coast or lowland-grown Douglas fir heartwood from 

 Everett, Washington, was taken in the green condition and soaked for 

 five days in each of a series of alcohols, 50, 95, and 100 per cent, re- 

 spectively, and then oven-dried (bone dry) at a temperature of 200^ F. 



A microscopic examination of the positions of the tori in the outside 

 of the block, where the penetration would be easiest and quickest, and 

 al-o of the center of the block, where penetration would be more diffi- 

 cult and slower, gave the results incorporated in Table 8. 



A com])arison of the positions of the tori in a piece of the material 

 in its green condition, as given in Table i with those in Table 8. shows 

 that the tori are in the same position after treatment with alcohol and 

 subsequent oven-drying as they were in the green specimen. In the 

 oven-dry material, not treated with alcohol, from the same specimen, 

 the majority of the tori in the summerwood were asjiirated as shown 

 in Table 3. 



