The Full Story
James Dewar was born in Kincardine, Scotland in 1842, one of the finest scientific minds Britain ever produced. He was nominated for the Nobel Prize 8 times and never won. In about 1892, working at the Royal Institution in London, he needed to store extremely cold liquefied gases. He built a double-walled glass vessel, pumped the air out from between the walls, and created the world's first vacuum flask. It worked perfectly.
He did not patent it. He built it as laboratory apparatus and shared it, as scientists shared apparatus. Reinhold Burger, a German glassblower who made flasks for the trade, developed a sturdier domestic version and patented it in 1903. From 1904 it was sold as the Thermos and made a fortune. Dewar went to court. He was widely acknowledged as the inventor, but acknowledgement without a patent carries no rights. He lost. He got nothing.
The word Thermos eventually became so common it lost its trademark in some countries altogether. It is now a generic noun, for a device invented by a Scottish scientist in a London laboratory who never received a penny for it. Dewar kept working. In 1898 he became the first to liquefy hydrogen, and his vessels laid the groundwork for an entire branch of physics. Cryogenics labs still call them dewars.
Why This Matters
The Dewar flask is the silent workhorse of twentieth-century science. Every cryogenics lab on earth uses a descendant of his vessel. Liquid helium is transported in them. MRI scanners depend on them. Astronauts drink coffee from them. He is also a lesson in a peculiarly British failing: the refusal to treat an idea as a thing to be owned. The result, in his case, was that the world got the thermos for free and he got nothing.
Key Facts
- ⚠Correction: the video says Dewar produced liquid hydrogen, then liquid nitrogen, and that the court agreed he was the inventor. Nitrogen had been liquefied by others before Dewar's work; his landmark first was liquefying hydrogen in 1898. And while he was widely acknowledged as the flask's inventor, the court case failed because he held no patent, not because the court formally ruled on his priority.