Whether Masers de Latude existed, or was but a creature projected on paper by some able enemy of La Pompadour, those famous and titillating _Mémoires_ are excellent documents—all but unique of their kind—of the prisons of bygone France. If the question be of the Bastille, of the Dungeon of Vincennes, of Charenton, or of Bicêtre, these pungent pages, with a luxuriance and colour of realistic detail not so well nor so plausibly sustained by any other pen, are always pat and complete to the purpose. To compare great things with small, it is as unimportant to inquire who wrote _Shakespeare_ as to seek to know who was the author of the _Mémoires_ of Latude. It is necessary only to feel certain that the writer of this extraordinary volume was as intimately acquainted with the prisons he describes as Mirabeau was with the Dungeon of Vincennes, or Cardinal de Retz with the château de Nantes. His book (an epitome of what men might and could and did endure under the absolute monarchy, when his rights as an individual were the least secure of a citizen's possessions) is the main thing, and the sole thing; the name and identity of the author are not now, if they ever were, of the most infinitesimal consequence. ------- A fine sample of the work of Bicêtre, considered as a machine for the manufacture of lunatics, is offered in the person of that interesting, unhappy genius, Salomon de Caus. A Protestant Frenchman, he lived much in England and Germany, and at the age of twenty he was already a skilled architect, a painter of distinction, and an engineer with ideas in advance of his time. He was in the service of the Prince of Wales in 1612, and of the Elector Palatine, at Heidelberg, 1614-20. In 1623 he returned to live and work in France, _dans sa patrie et pour sa patrie_. He became engineer and architect to the King. Eight years before his return to France, De Caus had published at Frankfort his _Raison des Forces Mouvantes_, a treatise in which he described "an apparatus for forcing up water by a steam fountain," which differs only in one particular from that of Della Porta. The apparatus seems never to have been constructed, but Arago, relying on the description, has named De Caus the inventor of the steam engine. It is not, however, with the inventive genius that we are concerned, but with the ill-starred lover of Marion Delorme. The minister Particelli took De Caus one day to the _petit lever_ of the brilliant and beautiful Aspasia of the Place Royale. Particelli, one of the most prodigal of her adorers, wanted De Caus to surpass, in the palace of Mademoiselle Delorme, the splendours he had achieved in the palace of the Prince of Wales. "At my charge, look you, Monsieur Salomon, and spare nothing! Scatter with both hands gold, silver, colours, marble, bronze, and precious stuffs—what you please. Imagine, seek, invent,—and count on me!"