300 
Journal of Agricultural Research 
Vol. XI, No. 7 
in connection with the temperature work already reported. In the 
temperature experiments, as has already been mentioned, the apples were 
placed in moist chambers of the usual laboratory style. The tops of 
the containers fitted loosely, nearly always leaving cracks of 0.5 mm. or 
more, yet preventing a free circulation of air. The moist chambers were 
usually opened once a week in note taking. With all of the different ex¬ 
periments and at all of the different temperatures similar apples were 
placed in the storage boxes by the side of the moist chambers, but held 
in baskets or other open containers that allowed a free circulation of air. 
The air in the boxes was gently circulated by fans, but its rate of move¬ 
ment was always less than % mile per hour. 
Gas analysis tests were made to determine the amount of carbon dioxid 
to which the fruit was exposed under the various conditions. The appa¬ 
ratus used in the determinations was that of Bonnier and Mangin (with 
modifications by Dr. William Crocker and GeorgeT. Harrington), and the 
methods, those outlined by Thoday (22). The tests showed that the free 
air in the 20° box had 0.42 per cent of carbon dioxid, that in the 15 0 box 
0.30 per cent, that in the 5 0 box 0.24 per cent, and that in the o° box 
0.02 per cent. The larger amounts of carbon dioxid in the warmer cham¬ 
bers is readily accounted for by the more rapid respiration of fruit at 
higher temperatures and by the better aeration that would naturally be 
secured in the colder boxes as a result of greater contrasts between the 
outside and inside temperatures. It was found impossible to obtain a 
satisfactory sample of air from the moist chambers, as the removal of the 
cover from such shallow vessels allowed too free an exchange of air. At 
the 15 0 temperature it was possible to obtain samples from jars that had 
been handled as moist chambers, having small openings left at the stopper, 
and in which the percentage of scald had run parallel with that in the 
regular moist chambers. There was no contrast between the amount of 
scald on the fruit in the bottom of these jars and that on the fruit near the 
top. The air samples were taken from near the bottom of the jar. An 
analysis of these samples showed that the air contained 4.28 per cent of 
carbon dioxid. While complete data could not be obtained at the differ¬ 
ent temperatures, it seems evident that there was several times more car¬ 
bon dioxid present in the air of the moist chambers than in the free air 
of the boxes. 
The air in the moist chambers was kept in a saturated condition by the 
addition of wet filter paper, the fruit, upon removal to a warmer tempera¬ 
ture, often being covered with a film of moisture or dotted with drops of 
water. The free air of the boxes was kept at a relative humidity of 85 
to 95 per cent. Water always stood in the bottom of the metal boxes, 
, but the fruit did not become perceptibly moist even upon removal for 
note taking; nor did it show any sign of withering even after several 
months of storage. In the experiments reported in figure 16, the 
relative humidity was lower, ranging from 55 to 70 per cent. In this 
