CHARACTER OF WASTES. . 7 
. 
(2) In case arsenic is present in the ores, as it often is and notably 
at Anaconda, it is given off in the fumes from the smelter in volatile 
form and deposited on the surrounding land and crops, where it may 
be present in sufficient amounts to poison cattle browsing on exposed 
ranges, or living on hay cut from such pasture. 
(3) The tailings from the water concentration of the ore and the 
slag, in a finely divided condition, are discharged on a dump heap 
through which the water from the plant is constantly percolating on 
its course to adjacent streams and the “slimes” are left in piles in 
the open air. Both the slime heap and the dump are also exposed to 
the percolating action of the rain. In consequence, the streams re- 
ceiving the waste water from concentrating and smelting plants con- 
tain a comparatively large amount of copper in suspension and are 
apt to hold some copper in solution. If these streams are used for 
irrigating purposes there is a possible source of injury to growing 
crops due to the action of the copper present. 
(4) Finely divided particles of the ore are discharged from the 
smelter stack and settle on the surrounding country. These fine par- 
ticles of flue dust may contain sufficient amounts of copper, lead, and 
zinc to injure vegetation, because of their toxic action through the 
medium of the soil and because of their caustic action on the foliage. 
While it is beheved by some® that the action of this so-called flue 
dust gives rise to the principal damage caused by smelter smoke, the 
writer is inclined to the opinion ? that such injury is not of great sig- 
nificance except in a very limited area about the smelter, and that an 
investigation of it is in most cases unnecessary, as the owners of smelt- 
ers are usually perfectly willing to admit damage, even beyond the 
area likely to be affected by the solid particles of copper, lead, and 
zinc in the flue dust. 
In the first case of this kind studied by the writer in the vicinity 
of Redding, Cal. (see Pl. I), and in the laboratory at Washington 
during 1903 and 1904, no complaint had been made of the injury 
from arsenic or from copper, so that the only problem considered 
was the action of sulphur dioxid and trioxid fumes on the surround- 
ing vegetation. The results of this study and the original investiga- 
tions connected therewith have been published,® but a résumé will be 
given, together with certain results obtained since the publication 
of the Redding investigations, in order that the reader may under- 
stand the present status of the work. 
@Fbaugh, J. Amer. Chem. Soc., 1907, 29: 951. 
b Haywood, Science, 1907, 26: 476. 
€U. S. Dept. Agr., Bureau of Chemistry, Bul. 89, Injury to. Vegetation by 
Smelter Fumes, 1905. 
