10 BULLETIN 1262, U. S. DEPARTMENT OF AGRICULTURE. 
12 hours, and the fifth at 24 hours. As soon as the test sets were 
removed, 2-inch blocks were cut from the center of each piece and 
cultures made from these. 
In the set exposed for three hours at 140° F. at saturation all the 
fungi were killed in the 4-inch test pieces except the blue-stain fungus 
(Ceratostomella sp.) in Pinus strobus and Thuja occidentalis, 
Trametes pint in Pinus strobus, Torula ligniperda in Tsuga can- 
adensis, and the brown ring-rot of Thuja occidentalis. Torula 
ligniperda was alive in the 1-inch and 2-inch pieces. These results 
indicate that in a few cases the penetration of heat into the centers 
of the 4-inch test pieces was not complete at the end of three hours, 
at least not sufficient to kill these particular fungi. The test pieces 
subjected to 140° F. for 6, 9, 12, and 24 hours all gave negative 
results when cultured. In the three-hour trial one 2-inch test piece 
infected with blue stain, when cultured, gave positive results with 
the fragment taken from the center of the block. Fragments taken 
nearer the edge of the block, however, showed no revival of the 
fungus in the cultures. 
RUN 10. 
One set of test material from both the Neopit and Oakridge ship- 
ments was placed in a Tiemann dry kiln for a period of three hours 
at 145° F. and at saturated atmosphere. 
Cultures made from the culture blocks at the end of the run 
showed all of the fungi to have been killed within the test pieces. 
RUN ll. 
Two sets of test pieces from both the Neopit and Oakridge ship- 
ments were placed in the usual manner in a Tiemann dry kiln. The 
pieces were subjected to a temperature of 150° F. at saturated at- 
mosphere for a period of one hour for the first set and two hours 
for the second set. : 
Of the set subjected to the above condition for one hour the 
following 4-inch pieces showed positive cultures: Polystictus hirsu- 
tus and Polystictus versicolor in Alnus oregona, blue stain in Thuja 
occidentalis and in Pinus strobus, Polyporus borealis in Acer sac- 
charum, Trametes pint in Larix laricina, Fomes igniarius in Acer 
gubrum, Fomes fomentarius in Betula papyrifera, and Polyporus 
schweinitziz in Pseudotsuga taxifolia. The remainder were negative. 
Of the set subjected for two hours all of the test pieces showed 
upon culturing no evidence that the fungi were alive. 
RUN 12. 
A set of test pieces, consisting of material from both the Neopit 
and Oakridge shipments, was placed on stickers in an open pile in 
a Tiemann dry kiln. The pieces were subjected to a temperature of 
170° F. at saturated atmosphere for 40 minutes. It took 20 minutes 
for the temperature to rise from 80° to 170° F. within the kiln after 
the charge was in and the doors closed. At the end of the run all 
the fungi were found to be dead. 
BRIEF SUMMARY OF THE TEST RUNS. 
Table 1, a summary of the results obtained.in the 12 runs, is based 
upon the examination of over 1,000 test pieces and the positive or 
. 
