But Mazas had a history. It was associated with the chief criminality of Paris for more than half a century, and a detailed account of it should be preserved. It was the first tardy effort of the French to follow in the path of prison reform, and was first opened on the nineteenth of May, 1850, to receive the seven hundred inmates of the then condemned La Force. Elsewhere prisons and their inmates had occupied a large share of public attention in the first half of the nineteenth century. The United States led the way with plans of amelioration, and the prisons of Auburn and Sing-Sing were conspicuous examples of the new order of things. In England, Millbank Penitentiary had been erected regardless of cost, after a scheme originated by John Howard and Jeremy Bentham, and had given place after thirty years of experiment to Pentonville, built under the auspices and personal supervision of some of the most distinguished Englishmen of the day. France alone lagged behind. The question was discussed there, but little more than talking was done. Two eminent publicists, MM. Beaumont and De Tocqueville, had visited America in 1837, and published a valuable monograph upon the penitentiaries of the United States. In 1840, an energetic and philanthropic prefect of Paris, Gabriel Delessert, converted, by his own authority, the boys’ prison of La Petite Roquette into a place of cellular confinement. Still, it was not till 1844 that the principle of isolation and separation for all prisoners was accepted even theoretically, in France. Five years more elapsed before Mazas, the first French prison built in accordance with modern ideas was ready for the reception of prisoners.