Essay on the Cause of Chemical Proportions
Give each element a one- or two-letter sign — and write every compound as a weighed recipe.
Every time you write H₂O, you are using a code a Swedish chemist invented in 1813 — the initials of the elements, spelled out in Latin.
The big idea
Jöns Jacob Berzelius gave chemistry an alphabet. He took each element and named it with one or two letters from its Latin name — O for oxygen, H for hydrogen, Fe for iron (ferrum), Na for sodium (natrium) — and then wrote compounds by stringing those letters together, with a small number to say how many atoms of each. Water became H₂O; chalk and rust and table salt each got a short, exact label. For the first time a compound's recipe could be written in a single line that any chemist, in any country, could read and any printer could set in type.
How it came about
Berzelius was the most exacting analyst of his age, working in Stockholm with apparatus he often made himself, weighing the products of reaction after reaction to pin down exactly how much of each element combined. He was trying to explain why elements always join in fixed proportions, and his answer was electrical: he thought every element was either electrically positive or negative, and that compounds were opposite charges clasping together — an idea he drew from the new battery, the voltaic pile, which could pull water apart into its electrical halves.
To handle the flood of measurements he needed a shorthand. John Dalton had drawn elements as little circles with dots and lines — charming, but impossible to print and hopeless once compounds got complicated. Berzelius swept them away and proposed letters instead. The theory behind his essay turned out to be wrong; the lettering turned out to be one of the most durable inventions in the history of science.
Why it mattered
A shared notation let chemistry become exact and cumulative. Once a formula could be written and printed unambiguously, results could be compared across borders, reactions could be balanced atom-for-atom, and the bookkeeping of matter became something you could check on paper. Berzelius also produced the best table of atomic weights of his century, so the symbols weren't just names — they carried numbers, and a formula told you the precise proportions by weight inside a substance.
An everyday picture
Think of how music went from being described in words — 'play a little faster here, brighter there' — to being written on a stave, where any musician anywhere can read the exact notes. Berzelius did that for matter. Before him, a compound was a paragraph of description; after him, it was a short, precise line of symbols — a score for substances that the whole world learned to read.
Where it sits in the story
Berzelius stands between Dalton's atoms (1808) and the modern chemical bond (see Lewis, 1916). Dalton said matter comes in atoms that combine in whole numbers; Berzelius gave those combinations a written language and accurate weights. His own explanation — that bonding is the attraction of electrical opposites — was overturned when chemists found electronegative chlorine could quietly replace electropositive hydrogen, and it even led him to reject Avogadro's molecules (see Avogadro, 1811), delaying that idea for fifty years. The theory faded; the alphabet he built has carried every chemical idea since, unchanged.
The chemical signs ought to be letters, for the greater facility of writing, and not to disfigure a printed book.
I shall take therefore for the chemical sign, the initial letter of the Latin name of each elementary substance.