Arsenical Poisoning of Fruit Trees. 
53 
this has been attributed to the lime. I have held in these cases that 
it was starvation rather than poisoning but this cannot be admitted 
in the case of the soil, an analysis of which has been given on a preced¬ 
ing page, without denying the evidence of this analysis and the actual 
productiveness of the soil. 
I have intentionally permitted these two subjects, the systemic 
poisoning by arsenic and the effects of lime, to merge into this 
broader form, because I believe that this form of the trouble is pri¬ 
marily due to arsenical poisoning modified by the presence of lime 
which exists in the soil in large quantities in the form iof calcic car¬ 
bonate and often forms, beneath the soil proper, a layer from two or 
three inches to two or more feet in thickness. 
I have shown on a previous page that these limey, virgin soils 
and also these marls contain arsenic, about one-tenth as much as the 
average orchard soil examined. 
To restate the case briefly. We have well cared for trees 
which are extremely small for their age. Their general condition is 
bad; some of the trees have died, these trees had no disease of the 
crown or roots and were not suffering from any recognizable, known 
disease; the wood is stained a light brown, an effect produced by 
arsenic; they make but little growth, another effect produced by 
arsenic; arsenic is present in the woody tissues of these trees and 
even in their fruit. Some of the trees have corroded crowns, a suf¬ 
ficient cause to account for the death of the particular trees. These 
cases are not considered in this place. It will be recalled that in dis¬ 
cussing irritant arsenical poisoning I pointed out that some of the 
arsenic found was probably gathered by the roots. Some of the 
trees show the splitting of the bark and bleeding, forming deposits 
rich in arsenic and lime. 
The arsenic is gathered from the soil by the roots as is shown by 
the peach trees and also by the elm which were never sprayed. This 
fact is again shown by the presence of arsenic in the fruit and leaves 
grown on trees which have not been sprayed this year. This arsenic is 
evidently carried to the leaver and the fruit from the soil by the solu¬ 
tions passing through the tree. The final question is how much arsenic 
can a tree tolerate and how long can it endure the amount that the 
roots gather and pass into the tree. These are questions to be solved. I 
am convinced that many trees have already reached the limit of their 
endurance and that this is the cause of their bad condition. I said in 
Bulletin 131, in reference to this subject of systemic poisoning and 
the action of lime as distinct from irritant arsenical poisoning, 
“These trees do not present the symptoms described for arsenical 
poisoning, though arsenic is very abundant. * * * These soils 
are marly or have a subsoil of this material and the presence of 25 
per cent of lime in the dried sap seems to me to be a very suggestive 
fact.” 
I add to this that the presence of arsenic in these soils equivalent 
to from 26 to 138 parts of arsenic acid per million of soil, and of arse¬ 
nic equivalent to 49 parts of this acid to each million parts of this dried 
