28 



BULLETIN 227, U. S. DEPARTMENT OF AGEICULTUEE. 



the test conditions outlined. In this table the preservatives are 

 arranged in the order of their toxicity, beginning with the most 

 toxic. 



Table II. — Killing point of Fomes annosus and F. pinicola for the various preserva- 

 tives, compared with coal-tar creosote, No. 1074, and zinc chlorid, No. 22S9. 



[Results marked with an asterisk (*) were not checked in duplicate, but they are approximately correct.] 



Fungus and preservative. 



Killing point. 



Per cent. 



Pounds 



per cubic 



foot. 



Ratio to 

 creosote. 



Ratio to 



zinc 

 chlorid. 



Fomes annosus (creosote killing point, 0.55 per cent; zinc- 

 chlorid killing point, 0.5 per cent;: 



Coal-tar creosote, Fraction II 



Sodium fluorid 



Creso 1 calcium i 



Coal-tar creosote, Fraction I 



Coal-tar creosote, Fraction III 



Zinc chlorid 



Coal-tar creosote, grade C 



Water-gas tar distillate No. 2235 (specific gravity 0.995). . . 



Wood creosote (Douglas fir) 



Wood tar (hardwood) 



Coal-tar creosote, Fraction IV 



S. P. F. carbolineum 



Avenarius carbolineum 



Coal-tar creosote, Fraction V 



Copperized oil 



United Gas Improvement Co. 1.07 oil, No. 1101 



None-Such Special 



Sapwood antiseptic 



Fomes pinicola (creosote killing point, 0.225 per cent; zine- 

 chlorid killing point, 0.75 per cent): 



Coal-tar creosote, Fraction III 



Coal-tar creosote, Fraction IV 



Coal-tar creosote, Fraction II 



Sodium fluorid 



Wood creosote (Douglas fir) 



Coal-tar creosote, Fraction I 



Coal-tar creosote, grade C 



Avenarius carbolineum 



Zinc chlorid 



Wood tar (hardwood) 



Coal-tar creosote, Fraction V 



Copperized oil 



United Gas Improvement Co. 1.07 oil, No. 1101 



None-Such Special 



0.225 

 .25 

 . 14-. 28 

 .30 

 *.325 

 .50 

 .55 

 * 65 

 *.65 

 *1.25 

 *3.30 

 4.5 

 5.25 

 *33 

 40 

 40+ 

 40+ 

 75+ 



.125 

 *. 125 



.15 

 .15 

 *20 

 .225 

 .225 

 .30 

 .75 

 .75 



*7.8 



40+ 



40+ 



50+ 



0.140 

 .156 

 0. 0S7-. 175 

 .187 

 .203 

 .312 

 .343 

 .405 

 .405 

 .7S 

 2.06 

 2.8 

 3.27 

 20.59 

 25 

 25+ 

 25+ 



.07S 

 .078 

 .094 

 .094 

 .125 

 .140 

 .140 

 .187 

 .468 

 .468 

 4.87 



25+ 



25+ 



31.2+ 



2.5 



2.2 



3.9-1.9 



1.8 



1.7 



1.1 



1 



.S4 



.84 



.44 



.16 



.12 



.104 



.017 



.014 



.014- 



.014- 



.007- 



l.S 



l.S 



1.5 



1.5 



1.12 



1 



1 



. 75 



.30 



.30 



.029 



. 0056- 



. 0056- 



.0045- 



2.2 



2 



3.6-1. 



1.7 



1.5 



1 

 .91 

 .76 

 .76 

 .40 

 .15 

 .11 

 .095 

 .015 

 .013 

 .013- 

 .012- 

 .007 



3.8 



3.3 



3.3 



2.5 



1 



1 

 .096 

 .019- 

 .019- 

 .0015- 



i Killing point lies between the limits given (1 and 2 drops of the preservative in 20 c. c. of the medium). 



Table II shows that of the 18 preservatives tested against Fomes 

 annosus 6 totally inhibit growth at or below 0.5 per cent, 5 between 

 0.5 and 3.5 per cent, 1 at 4.5 per cent, 1 at 5.25 per cent, and the 

 remaining 5 show extremely low toxic properties, requiring from 33 

 to 75 per cent. 



Sodium fluorid is particularly toxic, being slightly more than twice 

 as effective as zinc chlorid. 



Cresol calcium in these tests shows a high toxicity, and the poor 

 results reported against it in service tests ' are apparently due to a 

 change in chemical constitution or to leaching, which did not take 

 place under our method of testing. 



1 Unpublished report, Forest-Products Laboratory. 



