| Glucose. | Alcohol. | Carbonic Acid. | ||
| C₆H₁O₆ | = | 2 C₂H₆O | + | 2 CO₂ |
| 180 | = | 92 | + | 88 |
And the old authorities said, if 180 parts of glucose produce 92 of alcohol, 100 will produce 51.1111, thus:
180 : 92 :: 100 : x = 51.1111,
| leaving the balance to be accounted for by carbonic acid | 48.8889 |
| 100 |
And again, if it takes 100 parts of glucose to produce 51.1111 alcohol, how much does it take to produce 1 per cent. by weight?
51.1111 : 1 :: 100 : x = 1.9565.
These figures are now true only of that part of the sugar which is transformed into alcohol and carbon dioxide.
Different Authors.—Pasteur has shown that a portion of the glucose was changed into succinic acid and glycerine, and as the result of one of the experiments which he gives, out of a large number, it appears that 100 parts of glucose produce about 48.46 of alcohol, and it would require 2.063 to produce 1 per cent. of alcohol by weight, and 1.65 to produce 1 per cent. by volume.
But this eminent chemist’s experiments were conducted in the laboratory, and under the most favorable circumstances, so that no loss by evaporation could occur—conditions under which fermentation on a large scale is never carried on.
Dr. Guyot states that it takes about 1.5 per cent. of grape sugar to produce 1 per cent. of alcohol, which is even less than is required according to Pasteur, and is manifestly too little. And the statement has been made, that a must containing 20 per cent. of sugar will produce 13 per cent. of alcohol, which is impossible.