Arsenical Poisoning oe Fruit Trees. 
56 
Corrosive arsenical poisoning attacks the tree at the crown, below 
the surface of the soil and usually involves the' large roots also. The 1 at¬ 
tack is from the outside and causes the disintegration of the bark, thr. 
cambium is not destroyed until the corrosion has perforated the bark 
which is not loosened. Pear and apple trees are affected; the pear tree 
is, at least, as susceptible to the action of the arsenic as the apple tree. 
Some varieties of pears, as well as apples, seem more susceptible than 
others, but this is true only in a general way. The age of the tree at the 
time the first applications were made seems to have some effect upon the 
resisting power of the bark. The variety of soil may have some influence 
but it is not pronounced enough to be recognized with certainty. Very 
many, if not the greater part of our soils, contain arsenic. This is true 
of our virgin soils as well as of our cultivated soils. Our orchard soils now 
contain from 10 to 28 times as much arsenic as our virgin soils. 
No other agency known to us produces the observed results, but arsenic 
when applied in soluble form produces similar effects quickly. 
The first sign of trouble in the apple tree is an early ripening of the 
leaves, at least, one year before the death of the tree; in pear trees the foil- 
age ripens early and assume a deep purple color. 
The amount of arsenic present in the destroyed bark and in the woody 
tissues of such trees is as great as in cases in which it is known that ar¬ 
senic was the cause of death. 
The trouble is very general throughout the state and occurs in all kinds 
of soils which fact eliminates the question of seepage and, to a large extent, 
that of alkalis. 
While the alkalis may in some instances be present in the soil in suf- 
fcient quantities to produce a perceptible effect, we cannot, owing to the 
wide range of localities and the great variety of soils in which we meet 
the trouble attribute very great importance to their action. Their pres¬ 
ence, however, in soils undoubtedly tends to make the arsenic more readily 
soluble. 
In the case of trees which have not been sprayed but which have been 
grown as fillers in sprayed orchards, the wood contained arsenic. This 
is true, too, of young trees grown in soil which contains arsenic. This 
shows that the arsenic may be and is taken up with the nitrient solutions. 
The fruit grown on such trees, apples and pears, contain arsenic and also 
the leaves. The fruit and leaves grow and are shed each season this is not 
the case with the woody portions of the tree. 
Systemic poisoning is produced by this arsenic distributed throughout 
the tree, interfering with nutrition and growth of the tree and in some 
cases causing its death. 
The bleeding met with in trees on marly soils is probably due to ihe 
combined action of lime and arsenc. A study of the ash constituents con¬ 
tained in the wood of trees grown in marly soil and in a sandy loam 
shows a remarkable difference in the amount of ash, 2.00 per cent/ against 
1.17 per cent, of the wood and a very much lower percentage of potash, 14 .- 
298 per cent, against 26.621 per cent, of ash. The deposit produced by 
this bleeding is very rich in arsenic as it contains 49 parts of arsenic acid 
per million of the dried deposit. 
