20 BULLETIN 607, U. S. DEPARTMENT OF AGRICULTURE. 
penetration. Thus, in figure 11, the penetration at 210° F. was 
about two and one-half times that at 160° F., while the absorption 
PENETRANCE TESTS. 
(Data in Table 21.) 
3 
-•£ 
il- 
ls 
< in 
0. 

0.07 
0.06 
£0.05 
ml 
SORPTION- 
< 
5 
0.02 
O.OI 
* 
1 
$0 
1 
70 
1 
50 
1 
90 
2 
00 
2 
10 
2 
20 
TEMPERATURE— DEGREES FAR. 
FIG. 12,— The relation between absorptions and penetrations into longleaf pine using a mixture of 25 per 
cent creosote No. 4 and 75 per cent tar No. 5 at different treating temperatures. Time of treatment, 1 hour; 
pressure, 200 pounds per square inch. 
was 1.6 greater. In figure 12, with a mixture containing 75 per cent 
of tar, the penetration at 220° F. was also two and one-half times that 
at 160° F., while the absorption was twice as great. 
