From 1616 to the close of the reign of King James, Jonson produced nothing for the stage. But he "prosecuted" what he calls "his wonted studies" with such assiduity that he became in reality, as by report, one of the most learned men of his time. Jonson's theory of authorship involved a wide acquaintance with books and "an ability," as he put it, "to convert the substance or riches of another poet to his own use." Accordingly Jonson read not only the Greek and Latin classics down to the lesser writers, but he acquainted himself especially with the Latin writings of his learned contemporaries, their prose as well as their poetry, their antiquities and curious lore as well as their more solid learning. Though a poor man, Jonson was an indefatigable collector of books. He told Drummond that "the Earl of Pembroke sent him 20 pounds every first day of the new year to buy new books." Unhappily, in 1623, his library was destroyed by fire, an accident serio-comically described in his witty poem, "An Execration upon Vulcan." Yet even now a book turns up from time to time in which is inscribed, in fair large Italian lettering, the name, Ben Jonson. With respect to Jonson's use of his material, Dryden said memorably of him: "[He] was not only a professed imitator of Horace, but a learned plagiary of all the others; you track him everywhere in their snow. ... But he has done his robberies so openly that one sees he fears not to be taxed by any law. He invades authors like a monarch, and what would be theft in other poets is only victory in him." And yet it is but fair to say that Jonson prided himself, and justly, on his originality. In "Catiline," he not only uses Sallust's account of the conspiracy, but he models some of the speeches of Cicero on the Roman orator's actual words. In "Poetaster," he lifts a whole satire out of Horace and dramatises it effectively for his purposes. The sophist Libanius suggests the situation of "The Silent Woman"; a Latin comedy of Giordano Bruno, "Il Candelaio," the relation of the dupes and the sharpers in "The Alchemist," the "Mostellaria" of Plautus, its admirable opening scene. But Jonson commonly bettered his sources, and putting the stamp of his sovereignty on whatever bullion he borrowed made it thenceforward to all time current and his own.