RECENT WORK WITH HYDROCYANIC ACID GAS 213 
egist. ‘Through the courtesy of Director W. H. Jor- 
dan, the writer secured the following summary of the 
experiments. 
In regard to these tests, Professor Lowe says: 
‘Our work consisted principally of experiments in the 
orchard and with bud-sticks. The former were mainly 
for the purpose of determining the strength of gas re- 
quired to kill the scale during the winter and spring, 
and incidentally the effect of the gas upon the trees, 
and the latter to determine the effect of the gas at dif- 
ferent strengths upon fruit buds. The experiments 
in the orchard were divided into two series, as shown 
by the following summaries : 
WINTER TREATMENT 
Trees fumigated December 13-24; weather cloudy 
a Strength Time of 
TREES of gas exposure Results 
6 plum | 0.18 gramme | % hour |Scales not killed; trees uninjured 
VG oe 0.18 ee 11 oe oe “sé te ee oe 
Sir ake 0.25 s 14 ‘* |Many live scales found; trees uninjured 
8 ee 0.25 “e 1 “c ae “ee ae ae oe oe 
cnc. 0.30 te 146 ‘* |Scales dead; trees uninjured 
7 se 0.30 é 1 ae “a ae : “a “ee 
1 peach | 0.18 oa 14 ‘ (Scales not killed; trees uninjured 
| 0.18 ee I eubree dead 
il ee 0.30 ee % ee ae se 
1 ee 0.30 es 1 ce ee oe 
SPRING EXPERIMENT 
Trees fumigated June 6-8 and June 16-24; weather cloudy 
Strength Time of Results 
cee of gas exposure 
4 plum pas gramme 1g hour |Scales dead; trees uninjured 
4 se 0.1 ‘ 1 oe ae ac ae xs 
(ie os 0.25 $e lg ‘ {Scales dead; trees uninjured, except 
three trees, which showed slight in- 
jury to foliage 
1 ‘* |Sceales dead; foliage slightly injured 
0.30 ef 1% ‘ |Foliage slightly injured 
1 ae ae ae 
“ee 0.25 of 
wwe 
