Also see Ignition, a book on the history of rocket fuel development, which is a great read: https://library.sciencemadness.org/library/books/ignition.pd...
“it was magnificently hypergolic with many fuels. (I used to take advantage of this property when somebody came into my lab looking for a job. At an inconspicuous signal, one of my henchmen would drop the finger of an old rubber glove into a flask containing about 100 cc of mixed acid —and then stand back. The rubber would swell and squirm" a moment, and then a magnificent rocket-like jet of flame would rise from the flask, with appropriate hissing noises. I could usually tell from the candidate's demeanor whether he had the sort of nervous system desirable in a propellant chemist.)”