* * * * * _Sub._ And what's your mercury? _Face._ A very fugitive; he will be gone, sir. _Sub._ How know you him? _Pace._ By his viscosity, His oleosity, and his suscitability." Even in the fourteenth century, Chaucer (in the "Canon's Yeoman's Tale") depicts the alchemist as a mere cunning knave. A priest is prevailed on to give the alchemist money, and is told that he will be shown the change of base metal into gold. The alchemist busies himself with preparations, and sends the priest to fetch coals. "And whil he besy was, this feendly wrecche, This false chanoun (the foule feende him fecche) Out of his bosom took a bechen cole In which ful subtilly was maad an hole, And therein put was of silver lymayle An unce, and stopped was withoute fayle The hole with wex, to keep the lymayle in. And understondith, that this false gyn Was not maad there, but it was maad before." This "false gyn" having been put in the crucible and burned with the rest of the ingredients, duly let out its "silver lymayle" (filings), which appeared in the shape of a small button of silver, and so accomplished the "false chanoun's" end of deceiving his victim. The alchemists accumulated many facts: they gained not a little knowledge concerning the appearances of Nature, but they were dominated by a single idea. Living in the midst of an extremely complex order of things, surrounded by a strange and apparently capricious succession of phenomena, they were convinced that the human intelligence, directed and aided by the teachings of the Church, would guide them through the labyrinth. And so they entered on the study of Nature with preconceived notions and foregone conclusions: enthusiastic and determined to know although many of them were, they nevertheless failed because they refused to tread the only path which leads to true advances in natural science--the path of unprejudiced accurate experiment, and of careful reasoning on experimentally determined facts. And even when they had become convinced that their aims were visionary, they could not break free from the vicious system which bound them. "... I am broken and trained To my old habits: they are part of me. I know, and none so well, my darling ends Are proved impossible: no less, no less, Even now what humours me, fond fool, as when Their faint ghosts sit with me and flatter me, And send me back content to my dull round."[3]