SOME EFFECTS OF SODIUM ARSENITE 13 
Table 5. — Rate of leaching of sodium arsenate from soil 
Date sampled 
Sept. 28, 1922 
Oct. 8, 1922.. 
Oct. 18, 1922. 
Apr. 10, 1923. 
Total 
Arsenic 
precipita- 
found 
tion after 
treatment 
Per cent 
Inches 
0.676 

.423 
.06 
.222 
.56 
.258 
12.76 
Date sampled 
June 25, 1923 
Oct. 10, 1923. 
Nov. 17, 1923 
Apr. 12, 1924. 
Total 
Arsenic 
precipita- 
found 
tion after 
treatment 
Per cent 
Inches 
0.132 
18.32 
.100 
31.10 
.040 
33.40 
.056 
40.84 
It is apparent that the leaching of the arsenic from this surface 
soil was very rapid and extensive and that the greater part dis- 
appeared within a year of the application. Undoubtedly in more 
arid climates the leaching would have been less rapid, and in more 
humid climates it might have been still more rapid. However, Mc- 
George (35), working in Hawaii with an annual rainfall of about 
200 inches, found practically no leaching of small quantities of 
arsenic from the surface soil, even over a period of several years. 
The mineral constituents in the soil may play an important part in 
this, or it may be that a limited quantity of arsenic may be held in- 
definitely and only the excess leached out. 
At the time of the sampling on November 17, 1923, some of the 
soil was brought to the greenhouse and seeds of a few varieties of 
the common economic plants sown in it to determine whether arsenic 
would be taken up. The results are shown on pages 9 and 10 and in 
Plates I. II, and III. 
SODIUM ARSENITE AND FARM ANIMALS 
Incidental to the use of sodium arsenite in eradicating the common 
barberry, a number of fatalities among farm animals have occurred. 
Although very few compared with the number of treatments made, 
they are worthy of record as indicating the dangers in the use of this 
material and the precautions necessary to avoid loss. 
Analyses of barberry tissues showed such small quantities of ar- 
senic that little apprehension was felt from this source, but it was 
recognized that sodium-arsenite solution spilled on the grass might 
be dangerous. That this fear was justified was shown in one in- 
stance when a few bushes in a pasture were treated. Cattle had ac- 
cess to the pasture and they found a place about 2 feet in diameter 
where some of the solution had been spilled. A few ate not only the 
grass but quantities of the sand also, with fatal results. Analyses 
of the stomach contents showed the presence of arsenic. 
In another case in a different State two cows were killed by eating 
sand from around the base of a barberry plant to which sodium ar- 
senite had been applied. In this case a shallow trench had been dug 
around the base of the bush and the poison poured in it. The weather 
was hot and dry, and no rain had occurred during the week to wash 
the arsenic into the soil. As the farmer had agreed to keep his cattle 
out of the pasture for a week, the men neglected to fill the trench, 
with the fatal results noted. 
Another case of a slightly different nature occurred on another 
farm. Several small barberry plants were treated with the sodium- 
