Plate IV 
Fig. I. — Comparison of the Action of Sodium-Arsenite Solution 
Applied to the Roots and Tops of Tomato Plants 
The tips of the roots of the plant in the left-hand pot were dipped 1 inch for three minutes in 
an S-pound sodium-arsenite solution diluted 1 to 40. The tip of the stem of the plant in 
the center pot was dipped for the same length of time, and one leaf of the plant in the right- 
hand pot was dipped 
Fig. 2. — Small Barberry Treated with Sodium-Arsenite Solution 
The base of the stems was wet with the solution, and in drying some arsenic remained on the 
surface. Lambs gnawed the bark and secured sufficient arsenic to cause the death of several 
