Ars^nicai, Poisoning or Fruit Trrks. ii 
tJiis source. The care taken was in all ways as circumspect, so far 
as the analytical work was concerned, as though the examination 
of human viscera were in my hands. Another source of error lay 
in the danger of getting some particles of spray material with the 
bark of the sample. This was obviated by removing the bark from 
both the roots and branches, before taking the sample for analysis. 
In one case, that of a pear tree, the bark was examined; in this 
case the bark was smooth and sound enough to permit of its being 
washed with a stiff brush. It gave a fainter reaction for arsenic 
than the wood which it covered. 
With these statements it may fully suffice if I give the details 
of only two samples a little more fully. 
One taken from the trunk of a small pear tree ten years old. 
Section cut out 30 inches above the ground, bark entirely removed, 
wood quite generally stained but not deeply so like the roots or 
central portion of many of the branches of the apple trees. This 
section is shown in Plate IV., Fig. 3. The wood is hard but rasps 
easily. I took 60 grams, almost exactly two ounces, destroyed the 
wood by means of sulfuric and nitric acid; collected the arsenic as 
arsenate of Iron; dissolved in sulfuric acid and introduced it with 
proper precautions into an active Marsh apparatus and obtained 
arsenic corresponding to 2.55 parts of arsenic acid per million. 
Owing to unavoidable losses, the arsenic obtained is too low. 
The second one is a sample of a stump. I cleaned it thorough¬ 
ly by paring off all bark and soiled portions and rasping it. I took 
two ounces as before, proceeded in exactly the same manner and ob¬ 
tained arsenic corresponding to 12.77 parts of arsenic acid per mil¬ 
lion. Every sample was proceeded with in just as careful a manner 
as these two, and arsenic was easily proven to be present in the tis¬ 
sue of every sample, whether it was taken from the central, the 
intermediate or exterior portion of the root or limb. 
We have seen that the arsenic is accumulating in the soil, hav¬ 
ing already reached as large an amount as 61.33 parts of arsenic acid 
in a million of soil. 
I have stated in Mr. Whipple’s words, the manner in which the 
trees are affected and have given the description of what I myself 
found. 
Further we have shown that in these dying trees arsenic is 
present in the roots, the trunk and branches varying up to 12.77 
parts per million. 
ARSENIC IS THE CAUSE OE DEATH. 
So far the question. Is the arsenic really the cause of the cor¬ 
rosion of the bark beneath the ground, the killing of the bark on the 
trunk, the killing of the roots and the staining of the wood, in short 
is it the cause of death? has not been answered. I have stated 
