Table IV. Product of Fermentation.
| libs. | oz. | gros | grs. | ||
| 35 libs. 5 oz. 4 gros 19 grs. of carbonic acid, composed of | {Oxygen | 25 | 7 | 1 | 34 |
| {Charcoal | 9 | 14 | 2 | 57 | |
| 408 libs. 15 oz. 5 gros 14 grs. of water, composed of | {Oxygen | 347 | 10 | 0 | 59 |
| {Hydrogen | 61 | 5 | 4 | 27 | |
| {Oxygen, combined with hydrogen | 31 | 6 | 1 | 64 | |
| 57 libs. 11 oz. 1 gros 58 grs. of dry alkohol, composed of | {Hydrogen, combined with oxygen | 5 | 8 | 5 | 3 |
| {Hydrogen, combined with charcoal | 4 | 0 | 5 | 0 | |
| {Charcoal, combined with hydrogen | 16 | 11 | 5 | 63 | |
| 2 libs. 8 oz. of dry acetous acid, composed of | {Hydrogen | 0 | 2 | 4 | 0 |
| {Oxygen | 1 | 11 | 4 | 0 | |
| {Charcoal | 0 | 10 | 0 | 0 | |
| 4 libs. 1 oz. 4 gros 3 grs. of residuum of sugar, composed of | {Hydrogen | 0 | 5 | 1 | 67 |
| {Oxygen | 2 | 9 | 7 | 27 | |
| {Charcoal | 1 | 2 | 2 | 53 | |
| {Hydrogen | 0 | 2 | 2 | 41 | |
| 1 lib. 6 oz. 0 gros 5 grs. of dry yeast, composed of | {Oxygen | 0 | 13 | 1 | 14 |
| { Charcoal | 0 | 6 | 2 | 30 | |
| {Azote | 0 | 0 | 2 | 37 | |
| —— | —— | —— | —— | ||
| 510 libs. | Total | 510 | 0 | 0 | 0 |
Table V. Recapitulation of the Products.
| libs. | oz. | gros | grs. | ||
| 409 libs. 10 oz. 0 gros 54 grs. of oxygen contained in the | Water | 347 | 10 | 0 | 59 |
| Carbonic acid | 25 | 7 | 1 | 34 | |
| Alkohol | 31 | 6 | 1 | 64 | |
| Acetous acid | 1 | 11 | 4 | 0 | |
| Residuum of sugar | 2 | 9 | 7 | 27 | |
| Yeast | 0 | 13 | 1 | 14 | |
| 28 libs. 12 oz. 5 gros 59 grs. of charcoal contained in the | Carbonic acid | 9 | 14 | 2 | 57 |
| Alkohol | 16 | 11 | 5 | 63 | |
| Acetous acid | 0 | 10 | 0 | 0 | |
| Residuum of sugar | 1 | 2 | 2 | 53 | |
| Yeast | 0 | 6 | 2 | 30 | |
| 71 libs. 8 oz. 6 gros 66 grs. of hydrogen contained in the | Water | 61 | 5 | 4 | 27 |
| Water of the alkohol | 5 | 8 | 5 | 3 | |
| Combined with the charcoal of the alko. | 4 | 0 | 5 | 0 | |
| Acetous acid | 0 | 2 | 4 | 0 | |
| Residuum of sugar | 0 | 5 | 1 | 67 | |
| Yeast | 0 | 2 | 2 | 41 | |
| 2 gros 37 grs. of azote in the yeast | 0 | 0 | 2 | 37 | |
| —— | ——— | ——— | ——— | ——— | |
| 510 libs. | Total | 510 | 0 | 0 | 0 |
In these results, I have been exact, even to grains; not that it is possible, in experiments of this nature, to carry our accuracy so far, but as the experiments were made only with a few pounds of sugar, and as, for the sake of comparison, I reduced the results of the actual experiments to the quintal or imaginary hundred pounds, I thought it necessary to leave the fractional parts precisely as produced by calculation.
When we consider the results presented by these tables with attention, it is easy to discover exactly what occurs during fermentation. In the first place, out of the 100 libs. of sugar employed, 4 libs. 1 oz. 4 gros 3 grs. remain, without having suffered decomposition; so that, in reality, we have only operated upon 95 libs. 14 oz. 3 gros 69 grs. of sugar; that is to say, upon 61 libs. 6 oz. 45 grs. of oxygen, 7 libs. 10 oz. 6 gros 6 grs. of hydrogen, and 26 libs. 13 oz. 5 gros 19 grs. of charcoal. By comparing these quantities, we find that they are fully sufficient for forming the whole of the alkohol, carbonic acid and acetous acid produced by the fermentation. It is not, therefore, necessary to suppose that any water has been decomposed during the experiment, unless it be pretended that the oxygen and hydrogen exist in the sugar in that state. On the contrary, I have already made it evident that hydrogen, oxygen and charcoal, the three constituent elements of vegetables, remain in a state of equilibrium or mutual union with each other which subsists so long as this union remains undisturbed by increased temperature, or by some new compound attraction; and that then only these elements combine, two and two together, to form water and carbonic acid.
The effects of the vinous fermentation upon sugar is thus reduced to the mere separation of its elements into two portions; one part is oxygenated at the expence of the other, so as to form carbonic acid, whilst the other part, being deoxygenated in favour of the former, is converted into the combustible substance alkohol; therefore, if it were possible to reunite alkohol and carbonic acid together, we ought to form sugar. It is evident that the charcoal and hydrogen in the alkohol do not exist in the state of oil, they are combined with a portion of oxygen, which renders them miscible with water; wherefore these three substances, oxygen, hydrogen, and charcoal, exist here likewise in a species of equilibrium or reciprocal combination; and in fact, when they are made to pass through a red hot tube of glass or porcelain, this union or equilibrium is destroyed, the elements become combined, two and two, and water and carbonic acid are formed.
I had formally advanced, in my first Memoirs upon the formation of water, that it was decomposed in a great number of chemical experiments, and particularly during the vinous fermentation. I then supposed that water existed ready formed in sugar, though I am now convinced that sugar only contains the elements proper for composing it. It may be readily conceived, that it must have cost me a good deal to abandon my first notions, but by several years reflection, and after a great number of experiments and observations upon vegetable substances, I have fixed my ideas as above.
I shall finish what I have to say upon vinous fermentation, by observing, that it furnishes us with the means of analysing sugar and every vegetable fermentable matter. We may consider the substances submitted to fermentation, and the products resulting from that operation, as forming an algebraic equation; and, by successively supposing each of the elements in this equation unknown, we can calculate their values in succession, and thus verify our experiments by calculation, and our calculation by experiment reciprocally. I have often successfully employed this method for correcting the first results of my experiments, and to direct me in the proper road for repeating them to advantage. I have explained myself at large upon this subject, in a Memoir upon vinous fermentation already presented to the Academy, and which will speedily be published.