492 STUDIES ON APPLES. 
jars were weighed and filled with apples taken from the same lot. 
One of the jars was placed in cold storage at a temperature of about 
0° C. (32° F.); the second jar was placed in a cellar temperature of 
about 60° F.; the third jar was also placed in cold storage, but, instead 
of being supplied-with a current of air, it was sealed and not opened 
until September 19, 1903, when an analysis of the contents of the jar, 
both the apples and the gas, was made. 
In the case of the fruit in cold storage difficulty was experienced 
in several instances when the temperature read slightly below the 
freezing point, the water freezing in the tube connecting the two 
bottles. This difficulty was overcome by dissolving salt in the water 
employed to furnish a current of air. 
RESULTS OF RESPIRATION EXPERIMENTS. 
The results of the examination of the apples employed for the respi- 
ration experiment are given in the graphic chart shown in figure 12 
and in Table V. These results coincide in a general way with the 
experiments in common storage and in cold storage already described. 
The fruit kept at a higher temperature ripened much more rapidly 
than that kept in cold storage. Moreover, the sucrose reached a 
lower minimum and the invert sugar a higher maximum in the experi- 
‘ments conducted at the higher temperature. These facts also confirm 
those obtained in earlier experiments. As in the case of other experi- 
ments previously described (p. 39), the sucrose of the apples kept in 
cold storage reached a minimum about the same time (in this case 
June 16, 1903) that the invert sugar of the same apples reached a 
maximum. After that date the percentage of sucrose increased and 
the percentage of invert sugar decreased. It is again suggested that 
this may be due to the selective tendency of the rot of the apples, 
whether the rot was due to bacteria, fungus growths, or to physio- 
logical death; and further, that the more mature apples may be more 
subject to decay than the less mature, whatever the cause of the decay. 
During the progress of the experiments the carbon dioxid and 
water were determined at short intervals, usually daily, up to the 
time when the experiments at cellar temperature were discontinued 
owing to the exhaustion of the sample. At this time the apples in 
cold storage began to rot and the increased amount of carbon dioxid 
given out vitiated any conclusions which might have been drawn from 
the work had it been longer continued. The amounts of carbon dioxid 
given off from both jars are shown graphically in figure 12. On eom- 
paring the amount of carbon dioxid eliminated with the malic-acid 
curve it hardly seems possible that the carbon dioxid can be accounted 
for by the disappearance of malic acid, as several workers, notably 
Gerber (see p. 19), have considered to be the case. On the other 
hand, the curve representing the content of total carbohydrates, 
