EVALUATION OF WOOD PRESERVATIVES 



483 



pounds per cubic foot the over-all picture of the relative threshold 

 amounts of creosote at the time of treatment, the oil lost, and the calcu- 

 lated proportional parts of the residual oil — after weathermg — above 

 and below 3o5°C, are sho^vn graphically in Fig. 34. All of the data are 

 in terms of pounds per cubic foot. If one bears in mind that the thresh- 

 olds (Col. 5, Table XXXV) as given by the Madison investigators were 

 located by a combination of visual observation of the blocks and extra- 

 polation of straight lines through the weight loss data one may conclude 

 that in all of these tests the results were essentially the same for all the 



3/4 INCH 

 BLOCKS 



14 



SOIL- BLOCK TESTS 



LENTINUS LEPIDEUS 



(MADISON) 



13 • 



12* 



• FULL CELL 

 ▲ EMPTY CELL 



SEE TABLE Xyvv ^ 



COLUMN 1 FOR 



NUMBER REFERENCES 



5« 



2* 



3/4 INCH 

 STAKES 



OUTER 



INCH OF 



POSTS 



2 4 6 8 10 12 14 16 



THRESHOLDS IN POUNDS PER CUBIC FOOT 



Fig. 35 — Relative values of creosote thresholds by soil-block tests, ^-inch stake 

 tests, and post tests. 



I 



