Formulae Chemical

For the convenience of those who have occasion to refer to a compound substance containing two atoms of base, (as, for instance, antimonious acid in respect to its carbon,) the weight of two atoms of the base is given after the weight of the single atom.

Professor Whewell in an Essay on the Employment of Notation in Chemistry, observes, “I have no hesitation in saying, that in mineralogy it is utterly impossible to express clearly, or to reason upon, the chemical constitution of our substances, without the employment of some notation or other. Every one who makes the trial will find that, without a notation, his attempts to compare the composition of different minerals will be confused and fruitless, and that, by employing symbols, his reasonings may easily be made brief, clear, and systematic.”

After criticising the foreign notation as being grossly anomalous and defective, he adds the following list, which he hopes he has shown to be mathematically consistent and chemically useful. He has used the atomic composition adopted by Dr. Turner in his Chemistry.

Berzelius represents water {aqua) by Aq; for the sake of simplicity Whewell says he has used q. He also observes, “In the notation of Berzelius, the atoms of oxygen are indicated by dots placed over the symbol of the base. Thus, , are the protoxide and peroxide of iron, which he considers as having two and three atoms of oxygen respectively. This notation is compact and simple, but it is not consistent with algebraical rule, so far as the oxygen is concerned; and I conceive that, if this element be explicitly expressed, it ought to be done in the manner I have recommended, fe + 2 o, fe + 3 o, &c.” — Journals of Royal Institution.

I have omitted Professor Whewell's reasons, which he gives to show the superiority of his notation over those of foreign nations and that of Berzelius, as they are not of practical utility in printing; but I have given his list, which will be useful in printing mineralogical works in cases where the copy may be bad.