ELIMINATION OF LARV^ IN " KHANS." 
57 
The following table shows the number of fig-moth larva? that 
later developed from figs boiled in this experiment : 
Temper- 
ature. 
Immer- 
sion. 
Number 
of figs. 
Immediate effect. 
Larva? 
present 
Oct. 28, 
1910. 
Per cent 
killed. 
° C. 
100 
100 
100 
100 
100 
100 
Seconds. 
20 
20 
25 
25 
30 
30 
18 
18 
17 
17 
14 
14 
Larvse living 
do 
11 
«8 
7 
10 
o5 
10 
39 
56 
59 
41 
64 
29 
Mostly living 
do 
Mostly dead 
do 
a Omorga. 
Examination of the figs immediately following the immersion 
would seem to show that a much larger percentage of the larvae is 
killed by an exposure of 30 seconds in the water than by shorter 
exposures, though the number of larva? breeding from figs scalded 
for 30 seconds does not lead to the same conclusion. The percentages 
killed can not be accurate, since in figuring them it is assumed that 
each fig contained a single larva, when in fact the number of larvae 
in a fig is variable. Plainly an exposure of 30 seconds of infested 
figs in boiling water is not sufficient to kill all larva? within the figs. 
Unfortunately, this fact was not established by the emergence of 
larva? from the boiled figs until the season was too far advanced 
to make further experiments allowing longer exposures in the hot 
water. 
If larva? were not killed in figs immersed for 30 seconds in boiling 
water it was because the heat did not penetrate to the interior of 
the fig in that length of time, for contact with water at boiling 
temperature causes immediate death to any larva. To determine 
how many seconds or minutes are required after immersion for the 
interior of the fig to rise to the temperature of the water, the bulb 
of a high-temperature thermometer was inserted to the center of 
3 large figs successively, which were immersed in water at 100 ('. 
(212° F.) and the temperatures recorded every half minute. The 
fir>t fig was immersed in a large sterilizing kettle at a "khan" and 
the temperatures recorded for only 7] minutes. The others were 
immersed in a small vessel of boiling water in the laboratory and 
the temperatures recorded for periods of M5 minutes. 
