20 
BULLETIN 227, U. S. DEPAETMEXT OF AGRICULTURE. 
Fomes annosus: In one week, the radial growth of the check was 15 mm.; 0.05 per 
cent, 20 mm.; 0.1 per cent, 15 mm.; 0.15 per cent, 3 mm. In four weeks concentra- 
tions up to 0.15 per cent showed 20 to 30 mm. ; 0.2 per cent, about 2 mm. Thus, the 
rate of growth on 0.05 and 0.1 per cent concentrations equaled or exceeded that of the 
checks, but the higher concentrations produced a decided inhibition. The growth 
on the toxic media appeared very much as on the check. 
Fomes pinicola: In two weeks, the radial growth of the check was 40 mm. ; 0.05 per 
cent, 9 mm. ; 0.1 per cent, 4 mm. ; no growth on 0.15 per cent. After four to six weeks, 
no growth on 0.15 per cent. The growth on the toxic media was flurry, white, and quite 
similar in appearance to that on the check. 
Zinc chloric!. 
(PL IV, figs. 53 and 54.) 
[Laboratory sample No. 2239. Cooperator, Grasselli Chemical Co., Cleveland, Ohio. Commercial salt, 
meeting the specifications of the American Railway Engineering and Maintenance-of-YTay Association.] 
Tests. 
Times 
killing 
Concentration of the preservative (percent). 
Fungus. 
Num- 
ber. 
Dura- 
tion. 
point 
veri- 
fied. 
O.i 
0.2 
0.3 
I 
0.4 1 0.45 
0.475 
I 
0.5 j 0.6 
0.65 
0.7 
0.75 
Check. 
33 
33 
Weeks. 
5 to 8 
4 to 8 
. 1 
2 
4 
1 
1 
1 i 1 
1 

4 
F. pinicola 
4 
4 
4 l 
4 
Fomes annosus: In 18 days, the radial growth of the checks reached about 35 mm.; 
0.05 per cent, about equal to check; 0.15 per cent, 8 mm. : 0.3 per cent, 1 mm. There 
was usually no growth on higher concentrations until after about four weeks, and it 
was comparatively slight even after six to eight weeks, reaching only 1 to 8 mm. The 
toxic cultures generally were denser and of brighter tan color than the check. 
Fomes pinicola: In two weeks, the radial growth of the check reached 40 mm.; 0.6 
and 0.7 per cent, 10 mm. After four weeks, 0.6 and 0.7 per cent reached 35 mm. On 
the lower concentrations the growth was more fluffy than that on the check. 
Sapwood antiseptic. 
[Laboratory sample No. 1611. Cooperator, J. M. Long, Chicago, ill. Formula (bv weight, in water solu- 
tion): NaCl, 2.92 per cent: CaS0 4 , 0.246 per cent: ZnS0 4 +7 H 2 0, 0.246 per cent; CuS0 4 +5 H 2 0, 0.1S2 
per cent; FeS0 4 +4 H 2 0, 0.0605 per cent.] 
Tests. 
Times 
killing 
point 
-veri- 
fied. 
Concentration of the preservative (per cent). 
Fungus. 
Num- 
ber. 
Dura- 
tion. 
16§ 
25 
30 
50 
60 
75 
Check. 
Weeks. 
17 4 to 5 
4 
4 
3 
2 
2 
1 
Fomes annosus: In about three weeks the radial growth of check reached 40 mm.; 
50 per cent, 10 to 15 mm.; 75 per cent, very slight growth. Penicillium developed 
abundantly on 100 per cent. The preservative up to 25 per cent concentration 
showed a decided stimulating effect. 
The first concentration is based on the solution, as given above, which was prepared 
and submitted by the cooperator. Above 16f per cent it was necessary to use a more 
concentrated solution, and a strength six times the original formula was prepared. 
