26 BULLETIN 221, U. S. DEPARTMENT OF AGRICULTURE. 



Wood creosote (Douglas fir) . 

 (PI. Ill, figs. 32-37.) 



[Laboratory sample No. 1099. Cooperator, Logged-OfI Land Utilization Co., Seattle, Wash. Black 

 liquid, with a strong pyroligneous odor; specific gravity, 1.052 at 00° C; flash point, 45° C; burning 



Eoint, 85° C; contains 8.35 per cent water; 7.55 per cent distills below 100° C; 54.69 per cent distills 

 elow 245° C] 





Tests. 



Times 

 killing 

 point 

 veri- 

 fied. ' 



Concentration of the preservative (per cent). 



Fungus. 



Num- 

 ber. 



Dura- 

 tion. 



0.1 



0.125 



0.15 



0.2 



0.25 



0.4 



0.45 



0.6 



0.651 



Check. 



Fomes annosus . . . 

 F. pinicola 



55 

 26 



Weeks. 



4 to 7 

 4 to 6 





 



4 

 4 



4 



3 



4 



3 

 



2 



2 



1 



1 







4 

 4 



















1 These values are based on gum-arabic emulsions. 



Fomes annosus: In 11 clays the radial growth of the check reached 25 mm.; 0.15 to 

 0.30 per cent reached 3 to 6 mm. In 15 days, 0.1 per cent showed 30 mm. In four 

 weeks, 0.15 to 0.30 per cent reached 18 to 28 mm. Usually, from four to six weeks 

 were required for initial growth on 0.6 to 0.625 per cent. The growth on the toxic 

 media was dense, dark creamy, occasionally zonate. 



Fomes pinicola: In eight days the radial growth of the check reached 15 mm.; 

 0.025 to 0.075 per cent, 11 to 20 mm. In three weeks, 0.025 to 0.1 per cent covered 

 the plates; 0.125 per cent reached 17 mm.; 0.15 per cent 4 mm. In 34 days the 

 initial growth appeared on 0.175 per cent. The growth on the toxic media up to 

 0.125 per cent was white and luxuriant, exceeding that on the check. 



Cresol calcium. 



(PI. Ill, figs. 38 and 39.) 



[Laboratory sample No. 2086. Cooperator, Blagden, Waugh & Co., London, England.] 



Fungus. 



Tests. 



Times 



killing 



point 



verified. 



Concentration of the 

 preservative (per cent). 





Number. 



Duration. 



0.14 



0.28 



Check. 





8 



Weeks. 



4 to 7 



1 



4 







4 







Fomes annosus: In about two weeks the radial growth of the check reached 20 mm. ; 

 0.14 per cent, 3 mm. After three weeks the check showed 30 mm. ; 0.14 per cent, 11 

 mm. After six weeks, 0.14 per cent reached 30 mm.; no growth on 0.28 per cent. 

 The growth on the toxic media occurred in alternating light and dark zones. 



A diversion from the usual method of weighing the preservative was necessary 

 with this substance, since on sterilizing at 100° C. the preservative would form a hard 

 crust on the sides of the bottles. To obviate this difficulty, the average weight of a 

 drop from a small pipette was obtained (four tests). This was found to be 28 milli- 

 grams, the drops varying not over 2 or 3 milligrams. The preservative was then added 

 directly to the media bottles in quantities of one, two, three, or four drops, the killing 

 point lying between one and two drops, which corresponds to 0.14 and 0.28 per cent, 

 respectively. 



