Gunpowder needed potassium nitrate, and before industrial chemistry the only source was nitrate-rich earth from dovecotes, stables and cellar floors. English "petermen" carried royal warrants entitling them to dig up private property — even church floors — and were widely loathed for it. The trade collapsed when imported Chilean and Indian nitrates undercut it in the nineteenth century, and the Haber–Bosch process finally made nitrogen fixation a factory product rather than something scraped from the ground.
Saltpetre man no longer exists as a living trade. Here is what erased it, and which profession took on the work.
800 – 1661
Alchemy from Baghdad to Basel
The Islamic world turned alchemy into something recognizably experimental: the Jabirian corpus and al-Razi's manuals describe real apparatus, classify real substances and demand that ideas be tested at the bench. Latin Europe absorbed this literature through 12th-century translation centers such as Toledo, and for four centuries alchemy ran on royal patronage, genuine metallurgical skill and no shortage of fraud. Paracelsus redirected the art toward medicine in the early 1500s, insisting the point of chemistry was to make remedies, not gold — a step toward the laboratory science to come.
What else was happening then
1661
Boyle's Sceptical Chymist
Robert Boyle's book attacks both Aristotle's four elements and the alchemists' three principles, arguing that matter consists of moving corpuscles and that an element should mean a substance that analysis cannot break down further. Just as radically, Boyle published his methods openly instead of hiding them in alchemical cipher — the habit that made chemistry cumulative.
1789
Lavoisier's Traité élémentaire de chimie
Antoine Lavoisier's textbook lists 33 elements, names oxygen and hydrogen, states that mass is conserved in every reaction, and replaces alchemical jargon with systematic nomenclature — all built on obsessively precise balance measurements funded by his private tax-collecting fortune. Five years later, revolutionary France guillotined him for that fortune.
1808
Dalton gives chemistry atoms
John Dalton's A New System of Chemical Philosophy proposes that each element consists of atoms with a characteristic weight, combining in simple whole-number ratios. The idea turned recipes into arithmetic: a chemist could now calculate what a reaction should yield and check the answer on a balance.
1828
Wöhler makes urea without a kidney
Trying to prepare ammonium cyanate in Berlin, Friedrich Wöhler instead obtained urea — until then known only from living animals — and wrote delightedly to his mentor Berzelius that he could make urea "without the use of kidneys." The synthesis undermined the idea of a special vital force in living matter and helped open organic chemistry as a field.
Where that work lives now
The scientist who makes and measures matter itself — from Tapputi's Babylonian perfume still to today's robot laboratories, still the one who decides what the spectrum means.
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