RUPERT'S Drops, a sort of glass-drops with long andslender tails, which burst to pieces on the breaking offthose tails in any part; said to have been invented byprince Rupert, and therefore called by his name. Con-cerning the cause of this surprising phenomenon, scarceany thing that bears the least appearance of probabi-lity has been offered. Their explosion is attended inthe dark with a flash of light; and by being boiled inoil, the drops are deprived of their explosive quality.