Arsenical Poisoning of Fruit Trees. 
disintegration of the bark on the root shown very distinctly in Plate II 
Fig. 4, was continuous to the base of the tree. 'Here the bark became 
brown and sunken. This particular form of the injury extended some 
distance up onto the limb. Beneath this bark the wood was stained 
bi ow n. I he sunken part and stained wood is shown in Plate II, Fig. 
2. The interior portion of the remoter branches of this limb was 
stained brown. This is shown on Plate II, Fig. i-A, in longitudinal 
section, m Fig. 2 in transverse section. The other portions of this 
tree were pertectly normal, the bark was healthy, the woody tissues of 
both roots and branches showed no staining or “black hearted” con¬ 
dition. The healthy condition of the other roots and branches of this 
tree is also shown on Plate II by Figs. i-B and 3. The so called 
black heart is in some cases caused by freezing but this case cannot be 
explained in this way, for we know 7 its cause and can trace its course 
and action and the injury was done in the month of June. No one 
will, I think, suggest that these changes were subsequent to and a re¬ 
sult of death and not of the action of the arsenic for all parts of the, tree 
noui ished by roots feeding outside of the poisoned area, even sections 
of this one root, remained apparently healthy and those portions of this 
tree which I have not cut off are still healthy. 
I indicated clearly in Bulletin 131 that I was aware of the fact 
that this case, and all the cases do the same, raises questions regarding 
the course of nutrient solutions in the tree. 1 dismissed this whole 
subject with the following statements: “The course was direct and 
the flow of the poisonous solutions was confined to a comparatively 
narrow channel. * * I am not concerned about any theory of sao 
circulation, but am simply tracing the discoloring effect of the arsenic 
through the roots into this portion of the branches.” 
I have personal knowledge of four other trees injured by the same 
agent, sodic arsenite, in a similar manner. The facts in these cases 
are even more interesting than in the preceding. 
There had been fillers planted betwen the rows of apple trees. 
These fillers, plum trees, had been cut down, the owner poured 
one half teacupful of the sodic arsenite qolution on each of the four 
stumps to kill them and at the same time get rid of the arsenical 
solution. No effect was produced for the next two or three days, 
at the expiration of which time the orchard was irrigated. The state¬ 
ment of the owner and his wife is, that within fifteen minutes after 
the ii rigation water reached these stumps the leaves on one side of the 
largest of the four trees involved drooped and never recovered. The 
owner surmising the cause of the trouble dug a trench and cut off 
the roots of the tree on that side. The odor of the sap exuding from 
the wounds made on the limbs by the arsenic was very offensive. 
The fourth tree in this group presented an interesting case. Two 
limbs on one side of the tree were injured, portions of them were killed. 
There was a narrow strip running from the ground up into a big- 
limb of this tree and then divided, following two smaller limbs, break¬ 
ing out to the surface in an apparently erratic way. The limbs were 
