762 
Journal of Agricultural Research v 0 i. xxvn, no. ic 
place a pet cock between the gauge and the measuring tank in order to 
protect the gauge from the sudden increase in pressure when the gas is. 
released from the ethylene cylinder. D is the rubber hose outlet. To 
measure gas with the apparatus, valve E is closed and valve F is opened. 
As ethylene is forced over into B , the reading on the pressure gauge 
rises. If F is now closed and E opened, gas is released from the cylinder, 
and the pressure-gauge reading falls. After a few such operations B r 
of course, becomes filled with pure ethylene gas at atmospheric pressure. 
Gauge readings were calibrated by collecting and measuring the re¬ 
leased gas. In this particular case a reading of 10 pounds was equiva¬ 
lent to 1 cubic foot of gas. 
C The measuring apparatus 
was mounted on a wheel 
truck for convenience in 
gassing the various rooms 
or experimental lots of 
fruit. 
EFFECT OF TEMPERA¬ 
TURE ON RATE OF 
COLORATION 
Three of the large rooms 
previously mentioned were 
used in this experiment, 
the first being kept at 78° 
to 83° F. (average, 82°F.), 
the second at 64° to 69° F. 
(average, 68° F.), and the 
third at 5 2 0 to 6o° F. (aver¬ 
age, 57 0 F.). Heat was 
furnished by an automatic 
hot-water heater in the 
hallway in the basement. 
The hot water circulated 
in pipes attached to the 
side walls of the rooms and 
the temperature was regu¬ 
lated by a valve in the hot- 
water pipe line. Moisture 
for humidifying the rooms 
was produced by means of 
large atomizers operated 
by compressed air, which gave a very fine mist. Seventy-two boxes of 
green lemons, divided into three equal lots, were placed in the rooms. 
Every six hours 1 cubic foot of ethylene from the cylinder was meas¬ 
ured out into each room. 
The fruit in the room at 82° F. colored up in 4 days, that at 68° F. 
in 5 days, and that at 57 0 F. in days. In all lots, the color.was good. 
In the room at 57 0 F. the buttons were firmer and less discolored than 
those of the fruit in the other rooms. 
The effect of higher and lower temperature was tested in the laboratory 
with small quantities of fruit. At a temperature of 45 0 F. and with 
ethylene of a 1 to 1,000 concentration, no development of color took 
Apparatus for measuring ethylene from cylinder. 
