ARSENIC CONTENT OF FORAGE CROPS. 55 
Both in a southerly and in a westerly direction, in 100 per cent of 
the cases examined, the leaves and the ash of the injured trees con- 
tained larger percentages of sulphur trioxid than the leaves and the 
ash of uninjured trees. 
The observations made on the inspection tours in various direc- 
tions from the Washoe smelter considered in connection with these 
figures prove that the forests on public domain had been injured and 
were being injured by sulphur dioxid fumes previous to and during 
the summer of 1908. 
ARSENIC CONTENT OF FORAGE CROPS AROUND WASHOE 
SMELTER. 
The previous investigation made around the Washoe smelter in 
the summer of 1906 showed that the ores smelted contained arsenic, 
some of which escaped from the stack and settled on the surrounding 
vegetation. The investigation in 1908 was made to determine 
whether this arsenic settled on the range grass of the public domain. 
For purposes of investigation 33 samples of range grass were col- 
lected at distances varying from 2? to 15 miles from the smelter in 
different directions. All samples except one were taken from the 
public domain or National Forest land. As in the 1906 investiga- 
tion, determinations were made of total and water soluble arsenic 
and the results obtained calculated to the dry basis and expressed 
both as milligrams of arsenious oxid per gram of dry sample. and as 
erains of arsenious oxid per daily ration of 25 pounds. The results 
obtained are given in Table XIV. 
TaBLE XIV.—Arsenic content of range grass expressed as arsenious oxid, nearly all 
samples taken from National Forest or public domain. 
(Calculated to dry basis. ) 
| . + Water-soluble arse- 
| Arsenious oxid per— | nious oxid per— 
Soe Location and approximate distance from smelter. | | 
: Gram of |25pounds} Gram of | 25 pounds 
dry | (avoir.) of dry (avoir.) of 
sample. ie ration.| sample. | dryration. 
| 
“ NORTH OF SMELTER. 
6151 | Sec. 26, T. 5 N., R. 11 W., public domiain not Mg. | Grains. | Mog. Grains. 
National Forest, about 2? miles NN W ofsmelter. 0.046 | -0 | 0.014 2.5 
6155a) See. 12, T. 5 N., R. 11 W., public domain not | 
National Forest, about 53 miles N_of smelter... .014 25 . 004 7 
6149 | See. 10, T. 5 N., R. 11 W., public domain in 
National Forest, about 6 miles NNW of smelter. 021 | 3.7 010 1.8 
6152 | Sec. 8, T. 5 N., R. 10 W., public domain not Na- 
tional Forest, about 6 miies N o smelter_.____.- 035 | 6.1 027 4.7 
6150 | See. 9, T. 5 N., R. 11 W., public domain in Na- 
tional Forest, about 7 miles NNW ofsmelter. -- 014 | 2.5 | 014 2.5 
6153 | Sec. 2, T. 5 N., R. 11 W., public domain in Na- | | 
tional Forest, about 7 miles NNW of smelter in 
SEDI LEN oy Sie ee a oa re eae et at rE em en ae . 007 2 005 9 
6330 | Sec. 4, T. 5 N., R. 10 W., public domain not Na- 
tional Forest, about 7 miles NNE of smelter... - 027 4.7 .010 ie 
6154 | Sec. 34, T. 6 N., R. 11 W., National Forest, about | 
iemiiles "NUN W Ofsmel tenes s 2-2 ss) se ee ee 035 6.1 . 007 1.2 
a Protected by hill. 
