I am very happy in having an opportunity of setting history right about these remarkable events, and would not have the reader disbelieve my author’s account of them, from his naming either white gunpowder exploding when melted, or his making the earth about the pot take fire of its own accord; since, however improbable these accounts may appear to some readers, and whatever secrets they might be in Joe’s time, they are now well known in chemistry. As to the last, there needs only to mix an equal quantity of iron filings, finely powdered, and powder of pure brimstone, and make them into a paste with fair water. This paste, when it hath lain together about twenty-six hours, will of itself take fire, and burn all the sulphur away with a blue flame and a bad smell. For the others, what he calls white gunpowder, is plainly the thundering powder called by our chemists _pulvis fulminans_. It is composed of three parts of saltpetre, two parts of pearl ashes or salt of tartar, and one part of flower of brimstone, mixed together and beat to a fine powder; a small quantity of this held on the point of a knife over a candle, will not go off till it melt, and then it gives a report like that of a pistol; and this he might easily dispose of in larger quantities, so as to make it explode of itself, while he, the said Joe, was with his masters. Such is the explanation of the ghostly adventures of Woodstock, as transferred by Mr. Hone from the pages of the old tract, termed the Authentic Memoirs of the memorable Joseph Collins of Oxford, whose courage and loyalty were the only wizards which conjured up those strange and surprising apparitions and works of spirits, which passed as so unquestionable in the eyes of the Parliamentary Commissioners, of Dr. Plot, and other authors of credit. The _pulvis fulminans_, the secret principle he made use of, is now known to every apothecary’s apprentice. If my memory be not treacherous, the actor of these wonders made use of his skill in fireworks upon the following remarkable occasion. The Commissioners had not, in their zeal for the public service, overlooked their own private interests, and a deed was drawn up upon parchment, recording the share and nature of the advantages which they privately agreed to concede to each other; at the same time they were, it seems, loath to intrust to any one of their number the keeping of a document in which all were equally concerned.