Arsenical Poisoning or Fruit Treks. 
47 
the feeding ground of the trees. The question is an entirely different 
one when the subsoil is within 8 or 12 inches of the surface or 
the material constituting the subsoil is mixed with the soil to such an 
extent that it constitutes more than an eighth of the soil, as we some¬ 
times find to be the case. We have in the analysis of this soil 1.739 
per cent, of carbonic acid (CO2) enough only to form a little less than 
4 per cent, of calcic carbonate. This leaves a slight excess of lime 
to combine with the other acids. I have assumed this form of lime to 
exist in the soil as I take it that this is probably the most injurious 
form of lime usually met with in soils to which no arsenite of lime 
has been added or in which this salt does not exist. We do not 
positively know that carbonate of lime in such quantities is in the 
least injurious. 
The trees in this orchard are sick. A few of the trees have 
corroded crowns. This feature is on the increase. Some trees 
have already been killed. There are some cases of bleeding and the 
deposits, like the others of this kind, are rich in arsenic and lime. 
The trees not affected in either of these ways are small for their 
age and are not thrifty though the crowns are perfect. These trees 
have not suffered from fungi or insects or blight. There is no ex¬ 
cessive water, nor is the soil in such condition as to produce suffocation. 
Neither Prof. Paddock nor Prof. Whipple was able to detect any 
cause for the condition of the orchard and tentatively suggested 
that it might be due to starvation. The small size of the trees, the 
color of their bark and the small annual growth justify 
the general conclusion that the trees lack in proper nutrition, but 
this does not explain whether this lack is due to an insufficient sup¬ 
ply of food in the soil or an inability on the part of the tree to take up 
and assimilate the food. In so far as an analysis gives us.any adequate 
information on this subject, this soil is fairly well provided with the 
various elements of plant food and if the trees are starving it is not 
because the supply of food within the reach of their roots is inad¬ 
equate but because of forne other reason. I believe that the trouble 
is due to the action of arsenic, either alone or in conjunction with the 
lime. This orchard has been well cared for and diligently sprayed 
for a number of years, using at first Paris green, next, lime, sal soda 
and arsenic, and of late years arsenate of lead. 
I have shown that the soil, especially about the trees, is vciy 
rich in arsenic, as much as 138 parts arsenic acid per million, of soil 
being present; also that distilled water dissolves out of this soil about 
1.34" parts of arsenic acid. The rest of the soil is certainly heavily 
charged with arsenic, the sprayings having been frequent and heavy, 
placing it within reach of the feeding roots of the trees. That the 
trees may take up enough arsenic in this manner to do them injury is 
shown by the case of the elm tree and others which have been cited 
and there are still others which might have been mentioned. In ad¬ 
dition we have two very significant facts, first that the trees are sick, 
second, that the wood of these trees contains arsenic, the one in which it 
was determined 2.19 parts per million of woody tissue, as much as is 
