EVALUATION OF WOOD PRESERVATIVES 



481 



SEE TABLE XXXV , 



COLUMN 2 FOR 



NUMBER REFERENCES 



3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 

 TREATMENT RETENTION IN POUNDS PER CUBIC FOOT 



Fig. 33— Creosote losses in weathered, ^^-inch cube, southern pine sapwood 

 test blocks; relation of per cent loss of total creosote to original residue above 

 355°C and retention at treatment, Ib/cu ft. All treatments were made with toluene 

 creosote solutions. The total elapsed time from treatment to final reconditioned 

 weight was about 105 days, including 60 days outdoor exposure on the Laboratory 

 roof at Madison, Wis. See Table XXXV for number references. 



Table XXXV is a condensed set of data on fourteen lots of weathered, 

 creosoted %-inch cube blocks. All of the tests were run at the Forest 

 Products Laboratory at Madison, Wisconsin, in the Division of Forest 

 Pathology, under the direct supervision of the same investigator. Dr. 



Catherine G. Duncan 



36, 37, 



39, 41 



The test fungus was Lentinus lepideus, 



Mad. 534. Ten of the tests have been run in cooperation with Bell Tele- 

 phone Laboratories, and four have been run more or less concurrently 

 with other cooperators. The technique for handling the weathered blocks 

 has been essentially the same, and it has been rigidly controlled, except 

 for the vagaries of the weather itself, at all essential points. 



The data for the creosotes (Cols. 3 and 4), for the thresholds (Col. 5), 

 and for the amount of residual oil in the blocks at the time they were 

 placed in test (Col. 8), and the per cent and amount lost (Cols. 6 and 7) 

 are all taken from the published reports or from manuscripts either 

 ready^^ or in preparation for publication.'*^ The writer has calculated the 

 residues in the residual oils, and the respective amounts remaining above 

 and below 35o°C (Cols. 9, 10 and 11) in pounds per cubic foot, on the 

 assumption that all the loss occurred in the fractions boiling below 355°C. 

 Particular attention is directed to the figures in Col. 11 — the calculated 

 amounts remaining of the fractions boiling below 355°C. In terms of 



