August, ’24] 
DAVIS: HYDROCYANIC GAS FUMIGATION 
441 
evidence relative to the basis for the complaints and the possible remedies 
for the situation. 
The letters received by Mr. Simpson from prominent nurserymen 
and orchardmen from eight or ten states, were unanimous in condemn¬ 
ing the present methods used in treating nursery stock and in present¬ 
ing evidence to prove the injurious effect of the gas on trees. In our 
personal talks with nurserymen and orchardmen in Indiana similar 
views were expressed. Nearly all. admitted its effectiveness as a scale 
destroyer and that it was probably harmless to trees which were per¬ 
fectly dry at the time of fumigation but that it was impractical to 
always have trees in the right condition for fumigation and that varying 
results are unavoidable. 
We would quote a few extracts from letters received by Mr. Simpson 
which we know to have come from nurserymen and orchardmen who are 
reliable and who are themselves interested in preventing the spread of 
harmful insects. 
One writer says, “If fumigation is done when the trees are perfectly 
dry, both tops and roots, with chemicals of proper strength, and in the 
hands of a careful and competent man it is all right, but there have been 
more trees damaged by fumigation than have ever been benefited, in the 
writer’s judgment.” Another nurseryman writes: “After we began 
fumigating our stock we received a lot of complaints that the trees were 
not breaking bud and that they were practically losing from 90 to 100 
per cent of the stock we had delivered. We know from our own personal 
experience that under certain conditions nursery stock will probably 
not be injured from fumigation, but the conditions vary. One can 
hardly tell just when they are exactly right. We believe that if trees 
were thoroughly dried off, roots and top, before placing them into the 
fumigating room, and then watched very carefully, that there would 
probably not be any damage, but let there be the least moisture on the 
roots, or the twigs of the trees, and the fumigation is done according to 
the present formula, we are satisfied that injury will result. The great 
trouble with fumigation, as we see it, is that you are never certain just 
what you have done; whether you have killed the scale, if any, or 
whether you have not killed all the scale. There is no way to determine 
excepting to await results.” Most of the men answering Mr. Simpson’s 
inquiry reported specific cases of injury. The orchardmen were equally 
emphatic in their wish to plant only trees which had not been fumigated. 
The following extract expresses the view of at least one state in¬ 
spector: “This fall, one of the leading inspectors of a large fruit-growing 
