28 
BULLETIN 227, U. S. DEPARTMENT OF AGRICULTURE. 
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. 2239. 
{Results marked with an asterisk (*) were not checked in duplicate, but they are approximately correct.] 
Fungus and preservative. 
Killing point 
Ratio to 
Pounds 
creosote. 
Per cent. 
per cubic 
foot. 
0.225 
0.140 
2.5 
.25 
.156 
2.2 
0. 14-. 28 
0.087-.175 
3.9-1.9 
.30 
.187 
1.8 
*.325 
.203 
1.7 
.50 
.312 
1.1 
.55 
.343 
1 
*.65 
.405 
.84 
*65 
.405 
.84 
*1.25 
.78 
.44 
*3.30 
2.06 
.16 
4.5 
2.8 
.12 
5.25 
3.27 
.104 
*33 
20.59 
.017 
40 
25 
.014 
40+ 
25+ 
.014- 
40+ 
25+ 
.014- 
75+ 
.125 
.007- 
1.8 
.078 
* 125 
078 
1.8 
.15 
094 
1.5 
.15 
094 
1.5 
*20 
125 
1.12 
.225 
140 
1 
.225 
140 
1 
.30 
1S7 
. to 
.75 
468 
.30 
.75 
468 
.30 
*7.8 
4 
87 
.029 
40+ 
25+ 
. 0056- 
40+ 
25+ 
.0056- 
50+ 
31 
2+ 
. 0045- 
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 
Cresol 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; zinc- 
chlorid killing point, 0.75 per cent): 
Coal-tar creosote, Fraction Til 
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 
2.2 
2 
3. 6-1. J 
1.7 
1.5 
1 
.91 
.76 
.76 
.40 
.15 
.11 
.095 
.015 
.013 
.013- 
.012- 
.007 
5 
5 
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 x are apparently due to a 
change in chemical constitution or to leaching, which did not take 
place under our method of testing. 
Unpublished report, Forest-Products Laboratory. 
