[Note B: These radicals by a first degree of oxygenation form the animal oxyds, as lymph, red part of the blood, animal secretions, &c.—A.]
Sect. V.—Observations upon the Combinations of Oxygen with the Compound Radicals.
I published a new theory of the nature and formation of acids in the Memoirs of the Academy for 1776, p. 671. and 1778, p. 535. in which I concluded, that the number of acids must be greatly larger than was till then supposed. Since that time, a new field of inquiry has been opened to chemists; and, instead of five or six acids which were then known, near thirty new acids have been discovered, by which means the number of known neutral salts have been increased in the same proportion. The nature of the acidifiable bases, or radicals of the acids, and the degrees of oxygenation they are susceptible of, still remain to be inquired into. I have already shown, that almost all the oxydable and acidifiable radicals from the mineral kingdom are simple, and that, on the contrary, there hardly exists any radical in the vegetable, and more especially in the animal kingdom, but is composed of at least two substances, hydrogen and charcoal, and that azote and phosphorus are frequently united to these, by which we have compound radicals of two, three, and four bases or simple elements united.
From these observations, it appears that the vegetable and animal oxyds and acids may differ from each other in three several ways: 1st, According to the number of simple acidifiable elements of which their radicals are composed: 2dly, According to the proportions in which these are combined together: And, 3dly, According to their different degrees of oxygenation: Which circumstances are more than sufficient to explain the great variety which nature produces in these substances. It is not at all surprising, after this, that most of the vegetable acids are convertible into each other, nothing more being requisite than to change the proportions of the hydrogen and charcoal in their composition, and to oxygenate them in a greater or lesser degree. This has been done by Mr Crell in some very ingenious experiments, which have been verified and extended by Mr Hassenfratz. From these it appears, that charcoal and hydrogen, by a first oxygenation, produce tartarous acid, oxalic acid by a second degree, and acetous or acetic acid by a third, or higher oxygenation; only, that charcoal seems to exist in a rather smaller proportion in the acetous and acetic acids. The citric and malic acids differ little from the preceding acids.
Ought we then to conclude that the oils are the radicals of the vegetable and animal acids? I have already expressed my doubts upon this subject: 1st, Although the oils appear to be formed of nothing but hydrogen and charcoal, we do not know if these are in the precise proportion necessary for constituting the radicals of the acids: 2dly, Since oxygen enters into the composition of these acids equally with hydrogen and charcoal, there is no more reason for supposing them to be composed of oil rather than of water or of carbonic acid. It is true that they contain the materials necessary for all these combinations, but then these do not take place in the common temperature of the atmosphere; all the three elements remain combined in a state of equilibrium, which is readily destroyed by a temperature only a little above that of boiling water[39].
Table of the Binary Combinations of Azote with the Simple Substances.
| Simple Substances. | Results of the Combinations. | |
| New Nomenclature. | Old Nomenclature. | |
| Caloric | Azotic gas | Phlogisticated air, or Mephitis. |
| Hydrogen | Ammoniac | Volatile alkali. |
| {Nitrous oxyd | Base of Nitrous gas. | |
| {Nitrous acid | Smoaking nitrous acid. | |
| Oxygen | {Nitric acid | Pale nitrous acid. |
| {Oxygenated nitric acid | Unknown. | |
| {This combination is hitherto unknown; should it | ||
| {ever be discovered, it will be called, according to | ||
| Charcoal | {the principles of our nomenclature, Azuret of | |
| {Charcoal. Charcoal dissolves in azotic gas, and | ||
| {forms carbonated azotic gas. | ||
| Phosphorus. | Azuret of phosphorus. | Still unknown. |
| {Azuret of sulphur. | Still unknown. We know | |
| Sulphur | {that sulphur dissolves in azotic gas, forming | |
| {sulphurated azotic gas. | ||
| {Azote combines with charcoal and hydrogen, and | ||
| Compound | {sometimes with phosphorus, in the compound | |
| radicals | {oxydable and acidifiable bases, and is generally | |
| {contained in the radicals of the animal acids. | ||
| {Such combinations are hitherto unknown; if ever | ||
| Metallic | {discovered, they will form metallic azurets, as | |
| substances | {azuret of gold, of silver, &c. | |
| Lime | { | |
| Magnesia | { | |
| Barytes | {Entirely unknown. If ever discovered, they will | |
| Argill | {form azuret of lime, azuret of magnesia, &c. | |
| Potash | { | |
| Soda | { | |