166 
JOURNAL OF ECONOMIC ENTOMOLOGY 
[Vol. 16 
Another very important point to be considered in fumigation work 
is the kind of cyanid used. I venture to say that there are very few 
entomologists who can indicate off-hand the cyanogen content of Sodium 
Cyanid satisfactory for fumigation purposes. When recommending 
the use of Hydrocyanic-Acid Gas to nurserymen, all entomologists 
should clearly indicate the cyanogen content of the cyanid to be em¬ 
ployed, as well as the specific gravity of the Sulphuric Acid. The fact 
should also be borne in mind that the high grade Sodium Cyanid of 
today contains approximately one-third more available cyanogen than 
does high grade potassium. 
Another factor which should receive serious thought on the part of 
officials requiring fumigation is the temperature at the time the work 
is performed. The effect that low temperatures have on fumigation 
results was well brought out by Mr. R. I. Smith in his paper which 
he read yesterday. In view of the results secured by Mr. Smith, I am 
inclined to believe that much fumigation has taken place in the past at 
temperatures so low that the gas was ineffective against San Jose Scale 
and other pests which may be distributed on nursery stock. 
Another unfortunate situation which arises, is the inability of state 
entomologists to be present at the time the plants are fumigated. This 
work is turned over to the nurseryman, who probably assigns the actual 
fumigation work to a laborer. 
Mr. C. L. Marlatt: In connection with this round table discussion, 
it might be well for a mmoent to refer again to the proposition Mr. 
Rockwell presented to the Section. We are all in agreement with the 
suggestion and it is a matter that has been discussed many times at 
our meetings. In connection with the original effort to secure national 
plant legislation, the bill which was drafted some 25 years ago dealt 
chiefly with the idea of governing the movement interstate, of nursery 
stock. The foreign features of the bill were almost negligible. It was 
an effort to get just what Mr. Rockwell has now suggested, national 
legislation to be enforced in co-operation with the states, to regulate the 
movement interstate of nursery stock. 
The reason we failed to get this legislation 25 years ago was the lack 
of agreement of the nurserymen and others concerned. It may be 
advisable to call an interstate conference on the subject, to discuss it 
fully from the standpoint of the different state needs, and from the 
standpoint of the nursery interests, as a basis for a new bill to be present¬ 
ed to Congress; and with the support of the states and the other interests 
such legislation might now be obtained. 
