THE TOXICITY TO FUNGI OF VARIOUS OILS AND SALTS. 



21 



Coal-tar creosote, grade C. 



(PL I, figs. 5 to 9.) 



[Laboratory sample No. 1074. Purchased from the Creosote Supply Co., Chalmette, La. Liquid at room 

 temperature, 8.4 per cent water; specific gravity, 1.0483 at 60° C. ; flash point, 93° C. ; burning point, 100" 

 C; 11 per cent distills below 205° C; 54.1 per cent distills below275°C; 74.1 percent distills below 320° C] 







m • 





■ 



Tests. 



■B a 



Concentration of the preservative (per cent). 



Fungus. 





\*4 t ' 



































Num- 

 ber. 



Dura- 

 tion. 





o 



cm 



lO 



IN 



bo 



CO 



CO 



^ 



*ra 



lO 





o 



a; 









e r 



o 



c 



o 



O 



o 



o 



o 



o 



o 



o 



o 



o 







Weeks. 































44 

 21 



4 to 8 

 4 to 6 



l 



l 









2 

 1 



1 







1 



1 



1 



1 



1 







4 





3 



2 



1 



4 



















1 These values are based on gum-arabic emulsions. Later work, using the pure preservative, indicates 

 that the toxic point may fall somewhat lower. 



Fomes annosus: In 17 days the radial growth of the check reached about 40 mm.; 

 0.2 and 0.275 per cent showed initial growth only. In three to four weeks, 0.2 per 

 cent showed 10 mm.; 0.25 to 0.5 per cent, 2 to 3 mm. In six weeks, 0.525 per cent 

 showed only initial growth. In seven weeks, 0.5 and 0.525 per cent reached 2 to 9 

 mm. The growth on the toxic media was about the same in appearance as on the 

 check. 



Fomes pinicola: In two weeks the radial growth of the check reached about 40 mm. ; 

 0.075 per cent, 3 mm.; no growth above this point. In four weeks, 0.075 per cent 

 showed 25 mm. ; 0.1 per cent, 13 mm.; 0.15 per cent, 6 mm. After five weeks, 0.175 

 and 0.2 per cent reached 3 mm.; above this point all growth was inhibited. The 

 growth on the toxic media was dull white, with a crinkled edge. 



Coal-tar creosote, Fraction I. 



: (PL II, figs. 10 and 11.) 



[Laboratory sample No. 1094. Cooperator. Semet-Solvay Co.. Ensley, Ala. Light liquid at room tem- 

 perature; specific gravity, 0.934 at 60° C; flash point, 62° C; burning point. 69° C; 78.3 per cent dis- 

 tills below 215° C.l 



Fungus. 



Tests. 



Times 

 killing 

 point 

 veri- 

 fied. 



Concentration of the preservative (per 

 cent). 



Num- 

 ber. 



Dura- 

 tion. 



0.2 



0.225 



0.25 



0.275 



0.3 



Check. 



Fomes annosus 



F. pinicola 



33 

 13 



Weeks. 

 4 to 6 

 4 to 6 



3 

 1 



4 

 4 



4 

 



2 



1 







4 

 4 













Fomes annosus: In 10 to 14 days the radial growth of the check reached 20 mm.; 

 0.2 to 0.25 per cent, from 1 to 4 mm. In four weeks, 0.2 to 0.225 per cent reached 30 

 mm.; 0.25 to 0.275 per, cent, from 7 to 10 mm.; no growth at 0.3 per cent. The toxic 

 cultures produced a thin, stringy growth. 



Fomes pinicola: In two weeks the radial growth of the check reached 40 mm.; 

 0.2 per cent, 1 mm. In four weeks, 0.2 per cent reached 40 mm.; no growth above 

 this point. The toxic cultures produced a fluffy white growth, similar in appearance 

 to that on the check. 



