52 
Colorado Experiment Station 
young trees which may make some difference, but they are similar 
to ours only in containing a high percentage of lime. The potash in 
them is only a few tenths of one per cent higher than we find in the ash 
of our dead tree. I have no analysis of the Geneva soils though some 
were published in Bulletin 56, old Series. 
The effect of the marly soil seems to be to increase the percent¬ 
age of ash in the, wood and bark, to lower the percentage 
of potash present and to increase that of the lime. This marly soil 
has been sprayed regularly and heavily. The results give no con¬ 
clusive answer to the question had in mind when the work was un¬ 
dertaken, but the following facts present themselves. The trees 
grown on the sandy loam are thrifty and healthy so far as we are able 
to judge. The trees on the marly soil on the other hand are not 
thrifty. We find no bleeding in the case of the trees on the sandy 
loam while it is quite common in the trees on marly soils. The ash 
of the trees grown on the sandy loam contains much less lime and 
more potash than that of trees grown on marly soil. The deposits 
made by exuding juices of the bleeding trees contain 25.0 per cent, 
of lime and 49 parts of arsenic acid per million. These facts perhaps 
may not amount to satisfactory proof to some but they certainly point 
directly to either the lime or the arsenic or to their joint action as the 
cause of the unhealthy condition of the trees. As lime alone has 
not been observed to produce these results, confined almost ex¬ 
clusively to these marly soils, we are justified in attributing the 
trouble to their joint action. 
I cut ofif the, limb of a Jonathan tree on the 8th of April and on 
the 12th of May I removed 2.2 grams of a deposit. The aqueous so¬ 
lution of this deposit gave a very satisfactory test for arsenic. 
The trunk through which the juice had to pass was very short and 
the arsenic could scarcely have been gathered from the woody tis¬ 
sues of the tree. The elm root, taken at least six feet from the trunk, 
was quite rich in arsenic. No doubt can reasonably be entertained but 
that this arsenic and also the lime had been gathered by the roots. 
The cases mentioned are by no means isolated ones. In some 
orchards cases of Needing are numerous and severe, in others they 
may be absent. The orchards in which this occurs usually have a 
marly subsoil at a shallow depth. This bleeding is not confined to 
wounds made by trimming but frequently takes place from cracks in 
the bark as previously described. Some instances of this are met 
with in many of the orchards to which reference has been made. 
Healthy trees do not bleed in this manner and their juices do not 
form such deposits. Trees killed by irritant arsenical poisoning do 
not bleed in this manner, nor have I seen any deposit of this sort on 
trees injured by arsenic accidentally applied to them. This condition 
is not attributable to arsenical poisoning alone. This deposit is, 
however, rich in arsenic and lime and I infer from these facts that we 
have in these cases a systemic poisoning by lime and arsenic. 
It has been observed by orchardists that certain shallow soils 
underlaid by marl produce a yellowing of the leaves on apple trees; 
