10 
BULLETIN 1316, U. S. DEPARTMENT OF AGRICULTURE 
arsenic ; but, except in the case of the rye, there was a very noticeable 
reduction in the length and vigor of the roots as well as in the tops 
(PL III). The rye continued to grow for more than a month and 
apparently had adapted itself to conditions when the experiment 
was discontinued. 
The order of susceptibility of these plants was about as follows: 
Oat, pea, vetch, corn, barley, wheat, and rye. These observations 
agree with the results given by Voelcker (4-5) and show that al- 
though 0.04 per cent of arsenic in the soil did not prevent the ger- 
mination of seed, it affected and prevented the growth of all the 
seedlings except rye. 
ABSORPTION OF ARSENIC BY PLANT TISSUES 
ABSOKPTION THROUGH THE ROOTS 
A review of the literature indicated that arsenic may be absorbed 
by many kinds of plants. To what extent common barberry plants 
would absorb sodium arsenite applied to the soil was of interest, 
not only as an indication of the manner in which the chemical kills 
the plant but because cattle occasionally browse on these bushes and 
might become poisoned. Analyses therefore were made of a num- 
ber of treated plants. Table 3 contains the results. These barberry 
bushes were treated with the 8-pound sodium-arsenite solution ac- 
cording to the directions given by Thompson (44)- 
Table 3. — Quantity of arsenic found in various portions of barberry bushes 
killed with sodium-arsenite solution applied to the ground 
Date (1922) of— 
Percentage of arsenic found in portion of plant 
analyzed 
Location 
Treatment 
Collec- 
tion 
Roots 
Stems 
Leaves 
Fruit 
Proxi- 
mal 
Distal 
Proxi- 
mal 
Distal 
Pulp 
Seed 
Toledo, Ohio 
Marshall, Wis 
Richland Center, Wis 
Aug. 17 
Sept. 20 
Oct. 15 
(Untreated). 
Sept. 26. 
Sept. 30 
Nov. 2 
Sept. 30 
0.084 
.188 
.010 

0.019 
.019 


0.012 
.094 
.007 

0.019 
.024 
.016 

0.087 
.014 
.075 

0.004 
.009 






The variation in the quantities of arsenic absorbed by the plants 
at Toledo, Richland Center, and Marshall may be accounted for by 
a number of factors, among which are the date of treatment, varia- 
tions in the quantity of sodium-arsenite solution applied, the tex- 
ture and chemical properties of the soil, and the soil moisture. It 
was noted that the treatments at Richland Center were not so uni- 
formly successful in killing the barberries as those at Marshall and 
Toledo. 
To establish the range of toxicity of arsenic and to determine its 
intake by plants, several groups of different plants, varying from 
grasses to trees, were treated and subsequently analyzed for arsenic. 
The plants were treated with solutions of the same concentration 
that was used on the barberry, but the quantities were varied in 
