164 Report OF THE CHEMIST OF THE 
the required minimum percentage of acetic acid varies from 4 to 
4.5 and that of solids from 1.25 to 2. In New York the standard 
is placed at 4.5 per ct. of acetic acid and 2 per et. of cider 
vinegar solids. It is a matter of interest to notice how the results 
of our experiments harmonize with the established legal standard. 
PERCENTAGE OF ACETIC ACID IN NORMAL CIDER VINEGAR. 
In the 18 experiments made in casks, approximating to some 
extent the conditions normally prevailing in home-made cider 
vinegar, the acetic acid equalled or exceeded 4.5 per ct. within 
24 months in 11 cases; in 2 cases it required 33 and 56 months 
to exceed 4.5 per ct., while in the other cases the amount re- 
quired by legal standard was not reached until after 36 months. 
In the 18 experiments carried on in bottles, 4.5 per ct. of 
acetic acid or more was formed in 3 to 18 months in 11 cases and 
in 8 other cases later; while in 4 cases, experiments 17, 22, 34, 
36, the acetic acid did not reach 4.5 per ct. at any time. In 
experiments 17, 22, 24, 31, 33, 34, 35, 36, the acetic acid suffered 
loss by destructive fermentation. 
In all the materials used in our work, there was an abundance 
of sugar present to form an amount of acetic acid well above 
4.5 per ct. and this was, for the most part, converted into 
alcohol, as far as our work indicated. The loss appeared to occur 
in changing alcohol to acetic acid. 
Provided proper material is used, that is, pure, undiluted 
apple juice of ripe apples, and provided the processes of fer- 
mentation are properly managed, there should be no difficulty 
in obtaining cider vinegar containing 5 per ct. or more of acetic 
acid. The present legal requirement of 4.5 per ct. of acetic acid 
in cider vinegar is therefore entirely reasonable. 
PERCENTAGE OF SOLIDS IN NORMAL CIDER VINEGAR. 
The legal standard: of New York requires 2 per ct. of cider 
vinegar solids. In our 18 experiments made in casks, the amount 
of solids in the vinegar nearly reached or exceeded 2 per ct. 
in 6 cases, when the vinegar was 2 years old; in 12 cases, the 
solids were below 2 per ct. but in 7 cases rose to 2 per ct. later. 
In the 18 experiments carried on in bottles, the solids were 
above 2 per ct. in 5 cases when the vinegar was 18 to 21 
months old but dropped below 2 per ct. later; while in 13 
