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Glass-eating chemical projects in your home laboratory from Popular Science 1938 –

Etching your laboratory glassware is only one of the many possibilities offered by compounds of the active element fluorine. NOT long ago, a noted chemist told of a solvent powerful enough to dissolve nearly every known material. If the water on the earth were replaced with a liquid called selenium oxychloride, he said, we should have to carry umbrellas made of glass, platinum, or tungsten whenever it rained, for those are about the only substances that the fluid does not attack. There is a more familiar chemical, however, so corrosive that it could even eat its way through a glass umbrella. Its name is hydrofluoric acid, and it is one of the interesting compounds of the highly active element fluorine with which you will enjoy experimenting in your home laboratory.

Modern Mechanix » Thrilling Stunts with a Glass-Eating Chemical – Link.