156 Report OF THE CHEMIST OF THB 
the temperature was 55° and 60° F.; in all parallel experiments 
of this series (17 to 29) at higher temperatures, little or no loss 
was noticed in most cases. In these experiments, the mouth of 
the bottle used in each case was closed by the loose. insertion of 
a rubber stopper. In the set of experiments numbered 30 to 35, 
the mouths of the bottles were quite large and were not closed 
at all, practically, simply having a loose plug of cotton inserted, 
This condition favored ready access of air and probably accounts 
in large part for the general deterioration observed in this set of 
experiments. 
This destructive change in vinegar can easily be prevented, 
when once vinegar has been made. The acetic organisms all 
require oxygen for their existence and their activity can be pre- 
vented by excluding air. In actual practice, it is advised, when 
once the vinegar has reached a sufficient degree of acidity (4.5 
per ct. or more of acetic acid) to draw off or filter the vinegar 
and then place in a clean barrel, filling it as full as possible and 
putting the bung in tight. 
VARIATIONS IN VINEGAR MADE UNDER UNIFORM 
CONDITIONS. 
In experiments 17 to 21 and 25 to 27, the material was stored 
in each case in several quart bottles and in experiments 30 to 35 
we used five pint bottles in each case. It was noticed quite 
early in the work that the material in different bottles kept under 
like conditions was not behaving uniformly and the analyses 
given represent composite samples taken from the different bot- 
tles kept under the same’ conditions. At the close of the work, 
analysis was made of the material in each individual bottle and 
these are given in full in the appendix. We desire to use some 
of these data here to indicate how it is possible for quite differ- 
ent results to be obtained from different portions of the same 
material kept under the same uniform conditions of temperature 
and general treatment. Experiment 17 furnishes the most strik- 
ing illustration. In this case there were used four bottles, each 
holding a quart. The analyses were made when the vinegar was 
about five years old. At the beginning of the experiment portions 
of the same apple juice were placed in these bottles and these 
stood side by side under the same general conditions. 
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