A LABORATORY EVALUATION OF WOOD PRESERVATIVES 203 



fungus is equally resistant to all preservatives and gross errors are 

 inevitable unless cognizance is taken of this situation. Since it is 

 impossible to use all the organisms which destroy wood, a choice has 

 been made to include genera which are known to be of considerable 



Fig. 8 — Assay of a polychlor phenol showing effect of increasing concentration. 

 The test organism Lentinus lepideus. The growth ratings from left to right are 

 4-4, 3-3, 1-2, and V = no growth on specimen. 



tv^ 



Fig. 9 — Same range of concentration as in Figure 8 with U-10 as test fungus. The 

 growth ratings from left to right are 4-4, 3-4, 1-3 and 1-2. 



economic importance in the decay of timber or which have been 

 encountered in the actual decay of telephone poles, being sure to include 

 in any given test the fungi which past experience has shown to be 

 resistant to the type of preservative under consideration. Four 



