A choice collection of rare secrets and experiments in philosophy as also rare and unheard-of medicines, menstruums and alkahests : with the true secret of volatilizing the fixt salt of tartar / collected and experimented by the honourable and truly learned Sir Kenelm Digby, Kt., Chancellour to Her Majesty the Queen-Mother ; hitherto kept secret since his decease, but now published for the good and benefit of the publick by George Hartman.