Alchemical fire in a flaskThis interesting account of alchemical fire in a flask is from John French, The Art of Distillation, London 1651.
To keep fire in a glasse, that whilest the glasse is shut will not burne, but as soone as it it opened will be inflamed.
First extract the burning spirit of the salt of tin in a glasse Retort well coated; when the Retort is cold, take it out and break it, and assoone as the matter in it, which remains in the bottome thereof after distillation, comes into the aire, it will presently be inflamed. Put this matter into a glasse viall, and keep it close stopt.
This fire will keep many thousand yeares and not burne unless the glasse be opened: but at what time soever that is opened it will burne.
It is conceived that such a kind of fire as this was found in vaults when they were opened, which many conceived to be a perpetuall burning Lamp, when as indeed it was inflamed at the opening of the vault, and the letting in aire thereby which before it lacked, and therefore could not burne. For it is to be conceived that there is no fire burnes longer than its matter endures, and there is no combustible matter can endure for ever.
There may be many uses of such a fire as this, for any man may carry it about with him and let it burne on a sudden when he hath any occasion for fire.