20 FUMIGATION METHODS 
Hand was not hurt. Ato.75 gramme Ogon had ter- 
minals slightly injured, as shown in Fig. 2, while 
Spalding was killed to the ground, but later sent out 
shoots at the base. At I.00 gramme Ogon was again 
only slightly hurt, while Abundance was dead to the 
surface of the ground. From 1.00 to 1.35 Ogon was 
slightly injured on the terminals, as can be seen in 
Fig. 3. 
The general conclusions drawn from these tests 
with plum are (1) that no injury will result where 
normal dose is used for one hour or less on well- 
matured trees over two feet in hight, and (2) that 
some varieties are more resistent to injury from over- 
doses of gas than others. 
Peach trees.—The experiments upon peach trees 
were commenced April 26, 1899, after the buds had 
begun to swell. There were 250 trees, one-half of 
which were first-grade Peninsula Yellow, 4 to 5 feet, 
while the others were very small, varying from 1% 
to 2 feet high. ‘The trees were divided into lots of five 
each, and both grades treated from 0.25 to 1.45 
grammes cyanide per cubic foot, 0.05 gramme being 
added each time. In every instance the short grade 
trees, known as ‘‘ whips,’’ were killed outright, or the 
tops were killed, sending out few feeble shoots near the 
ground later. This corresponded to results obtained in 
1898, that June-budded peach and plum, and small whip- 
like trees from 1% to 2% feet, can not withstand more 
than o.18 gramme for half an hour. On the other 
hand, with large trees there was no perceptible injury 
from 0.25 gramme up too.50 gramme. At the latter 
strength, double the normal, the terminals were injured 
