Arsenical Poisoning of Frl t it Trees. 
19 
spray. It is mixed with lime to make the arsenic insoluble, though 
a very marked quantity of arsenic remains in solution in the alkaline 
liquid. This is contrary to general belief. I have had two lots of 
this preparation made with very excessive quantities of lime. Two 
hundred cubic centimeters of the supernatant solution gave a good 
test for arsenic by Reinsch’s test. The sodic arsenite is not itself used 
for the purpose of spraying the trees but is added to the milk of lime 
to make the lime, sal soda and white arsenic preparation. 
Dr. S. M. Bradbury, Horticultural Inspector of Mesa County 
for eight years, makes the following statement which is used with his 
permission. “Bands had been used in a certain orchard and on adopt¬ 
ing the lime, sal soda and arsenic spray these bands were left on the 
trees, some of them for two or three years. Some of these trees 
died and on examining the bands we found that the bark beneath the 
bands had been entirely eaten up. The lime and arsenic had collected 
under the bands and destroyed the bark." 
I know of another tree within a few feet of which the owner had 
mixed his spray material for several years in succession. This tree 
died and its wood was rich in arsenic. In this case arsenate of lead 
was used as far back as I have any information—about four years be¬ 
fore the death of the tree. 
I will cite but .one more, though there are a few other instances 
which might be given. A man emptied his spray tank, containing 
arsenate of lead, about six feet from an apple tree; that side of the 
tree died. I did not take and analyze any portion of this tree becau <c 
the owner did not wish me to deform the tree as he was sure he could 
cure it. The effects in these cases were in the main the same as in the 
cases killed by sodic arsenite, disintegration of the bark, the staining 
of the woody tissue, the production of a “black heart." and the production 
of a yellowish red bark frequently with longitudinal cracks. It will 
be remembered that I did not ^ee the trees described by Dr. Bradbury, 
though I know the orchard very well and can testify that it has been 
in very bad condition for several years past. His description which 
I believe to be entirely reliable tallies exactly with what we find in the 
other instances. It is only through accidents that we have opportun¬ 
ity to observe the effects of sodic arsenite on 16 or 18 year old trees 
in commercial orchards, but the lime arsenite and the lead 1 arsenate 
have been applied plentifully to our commercial orchards for years 
past and the action of these two may be found in almost any commer¬ 
cial orchard from 12 to 18 years old. No distinction can be made so far 
as I have observed between the action of these two sprays, except tha + 
the lime salt being more readily soluble than the lead salt probably has 
done the greater amount of injury to our orchards. 
We have then a fair amount of evidence obtained by direct obser¬ 
vation of the effect of arsenic in the three compounds, sodic arsenite, 
lime, sal soda and white arsenic, and lead arsenate, upon the bark, 
the woody tissues and the life of the tree. The sodic arsenite 
acts quickly, causing the death of all parts of the tree to which it may 
be carried; it causes the disintegration of the bark, especially of the 
