"On the 27th December 1666, in the forenoon, there came to my house a certain man, who was a complete stranger to me, but of an honest grave countenance, and an authoritative mien, clothed in a simple garb.... He was of middle height, his face was long and slightly pock-marked, his hair was black and straight, his chin close-shaven, his age about forty-three or forty-four, and his native province, as far as I could make out, North Holland. After we had exchanged salutations, he asked me whether he might have some conversation with me. He wished to say something to me about the Pyrotechnic Art, as he had read one of my tracts (directed against the Sympathetic Powder of Dr Digby), in which I hinted a suspicion whether the Grand Arcanum of the Sages was not after all a gigantic hoax. He, therefore, took that opportunity of asking me whether I could not believe that such a grand mystery might exist in the nature of things, by means of which a physician could restore any patient whose vitals were not irreparably destroyed. I answered, 'Such a medicine would be a most desirable acquisition for any physician; nor can any man tell how many secrets there may be hidden in Nature; yet, though I have read much about the truth of this art, it has never been my good fortune to meet with a real master of the alchemical science.' ... After some further conversation, the Artist Elias (for it was he) thus addressed me: 'Since you have read so much in the works of the alchemists about this stone, its substance, its colour and its wonderful effects, may I be allowed the question, whether you have not prepared it yourself?' On my answering his question in the negative, he took out of his bag a cunningly-worked ivory box, in which were three large pieces of substance resembling glass, or pale sulphur, and informed me that here was enough of the tincture for the production of twenty tons of gold. When I had held the precious treasure in my hand for a quarter of an hour (during which time I listened to a recital of its wonderful curative properties), I was compelled to restore it to its owner, which I could not help doing with a certain degree of reluctance.... My request that he would give me a piece of his stone (though it were no larger than a coriander seed), he somewhat brusquely refused, adding, in a milder tone, that he could not give it me for all the wealth I possessed, and that not on account of its great preciousness, but for some other reason which it was not lawful for him to divulge.... Then he inquired whether I could not show him into a room at the back of the house, where we should be less liable to the observation of passers-by. On my conducting him into the state parlour (which he entered without wiping his dirty boots), he demanded of me a gold coin, and while I was looking for it, he produced from his breast pocket a green silk handkerchief, in