07/09/2026
Two hundred and seventy years ago a young Scot in Edinburgh did something nobody had managed before. He weighed a gas. 🏴
Joseph Black was born in 1728 to a Scottish merchant family settled at Bordeaux, and he was sent home to be educated, first at Glasgow and then at Edinburgh. In 1754 he presented a medical thesis there on a white powder called magnesia alba, and buried inside that quiet piece of student work was one of the great discoveries of the age. Heating the powder made it lighter. Something was escaping. Black caught it, measured it, proved it would smother a candle, and named it fixed air. We call it carbon dioxide. He had shown that air is not one single thing but a family of different gases, each with its own weight and its own character.
Seven years later at Glasgow he did it again. Ice sitting in a warm room takes a long time to melt, and while it melts it stays stubbornly at the same temperature. Black worked out why. Heat was pouring into it and going somewhere invisible, hiding inside the change from solid to liquid. He called it latent heat, the heat that lies concealed. A young instrument maker at the same university named James Watt was listening carefully, and what he did next with a steam engine rearranged the world. Black went on to hold the chair of chemistry at Edinburgh for more than thirty years and died there in 1799, one of the quiet giants of the Scottish Enlightenment. 🪻
A merchant's son from a Scottish family abroad, sent home to learn, who ended up teaching the world how to measure the things it could not see. The blood remembers.
Every country has its famous inventors. Which Scot do you think has been most unfairly forgotten?