Nitroglycerin

Glycerin is a harmless syrup. You can eat it. Nitrate it and you get a pale oily liquid that detonates if you jolt it — and the difference between the two is not magic, it is bookkeeping. Nitration bolts the oxidiser directly onto the fuel molecule, so the reaction no longer has to wait for air to arrive.

That bookkeeping is a number you can calculate, and this blueprint calculates it. Glycerin's oxygen balance is about −122 %: it is starved of oxygen and needs a great deal of air to burn. Nitroglycerin's is +3.5 % — it carries a slight surplus. Every atom it needs is already in the molecule, which is why it does not burn so much as rearrange, all at once.

Ascanio Sobrero made it at Turin in 1847 and was appalled by it. He was scarred by an explosion, sat on the discovery for over a year, and then published rather than patented — which is why there is no patent number on this page. He wrote that he was "almost ashamed to admit to be its discoverer".

⚠ This blueprint is arithmetic and molecular models. It contains no synthesis of any kind, and needs none — the whole argument is in the atom count.