New YorK AGRICULTURAL EXPERIMENT STATION. 301 
possible to determine whether the specimens found had survived 
the fumigation. 
Under folding fumigators.—Five hundred and fifty tests were 
made during the winter of 1900-1901. At time of treatment 
many of these trees were infested. Only one was found where 
there was positive proof that the scale had survived the 
fumigation; this was a peach treated March 19th (a windy day), 
with four-fifths ounce of potassium cyanide per 100 cu. ft. (.25 
gram per cu. ft.) for 35 minutes. On August 26th, it was found 
that the lower branches which lay close to the ground were 
badly infested with living specimens. Adjoining trees showed 
a few living scales on December 7th. These were not badly 
infested trees before treatment, and the specimens were found 
-only on sides next the previously infested tree showinyz quite 
conclusively that they became infested from it. 
In only one other instance has any trace of living scale shown 
itself as late as December 7th. This was on a tree which was 
slightly if at all infested before fumigated. Only three speci- 
mens were found. All indications are that this tree became 
infested after treatment, possibly from the previously mentioned 
tree, although about ten rods to the north of the latter. 
As shown in the discussion of diffusion, it is possible thut 
hydrocyanic acid gas was absorbed by the moist ground rapidly 
enough so that individual scales on the lower branches survived 
the treatment, but if this was the case similar results ought to 
have been obtained from some of the other 181 tests made on 
peach with same amounts of cyanide of potassium, even though 
all the trees were not infested at time of treatment. It seems 
more probable that an accident during fumigation of this one 
tree must have occurred. Either the wind caused the fumigator 
to lift frequently during the period of exposure, or an error was 
made in the amount of chemicals used. 
Before drawing conclusions it should be stated that the plums 
found infested after treatment were fumigated after the tents 
were much the worse for wear and badly in need of reoiling. 
In fact, at time of treatment of this small orchard there was 
