“[_His Majesty will be_] eighty-two years of age on his next birthday.... All here admired my Lord Viscount’s portrait, and said it was a masterpiece of Rigaud. Have you seen it? It is [_at the Lady Castlewood’s house in Kensington Square_]. I think no English painter could produce such a piece. “Our poor friend the Abbé hath been to the Conciergerie [_where his friends may visit him_. _They are to ask for_] a remission of his sentence soon. “[_The Lord Castlewood_] has had the affair of the plate made up and departs for England. “Is not this a dull letter?...”—Bk. III. Chap. 8. This letter shows very clearly that the Argyle steganogram is one which it is almost impossible to solve without the key, unless the matter to which it relates is known beforehand[341]—a difficulty to which Bacon’s correspondent was not exposed, for he knew well what the subject of Bacon’s communication would be. Here, then, we should have found ourselves left in utter darkness were it not for a ray of light afforded by Chap. XI. There we are told that _something_, in connection with saltpetre and sulphur, produces an explosion,[342] and we know that this _something_ is charcoal. Since Chap. XI. is concerned with the composition and effects of this mixture, what more probable than that Chaps. IX. and X. should deal with its ingredients separately—or at least with saltpetre and charcoal, for sulphur was so simple and common a drug that Bacon was not likely to dwell upon it? Now, towards the end of Chap. X. Bacon speaks without disguise of charcoal under the name of the wood from which it is made,[343] and mentions the two trees, hazel and willow, which give the best. He significantly adds that when charcoal is added to proper proportions of certain other substances, something noteworthy happens (_si vero partes virgulti coryli aut salicis multarum justâ rerum serie apte ordinaveris, unionem naturalem servabunt: et hoc non tradas oblivioni, quia valet ad multa_). Since, then, charcoal is one of the subjects of these two chapters, it becomes all the more probable that saltpetre forms another. Bacon was writing but a few years after its discovery, and nothing could be more natural than that the great alchemist should bestow his attention upon the preparation of the new salt. This hypothesis explains simply and completely the most remarkable feature of Chaps. IX. and X.—the series of common and well-known alchemical terms and phrases, referring undoubtedly to the preparation of either saltpetre or gold, which are scattered and hidden among incoherent maunderings about chalk and cheese, philosophic eggs and Tagus sand, Adam’s bones and aperient medicine. But how could the preparation of gold lead up to the recipe for an explosive with which Chap. XI. ends? There is no connection whatever between gold and gunpowder, while the connection between saltpetre and gunpowder is of the closest possible kind. Before giving a recipe for gunpowder it was absolutely necessary