One may venture to say now, without fear of contradiction, that that law was one of the most valuable that has been placed on the statute-book in modern times. And yet no law proved more unpopular than this was, for years after it had been enacted. But Mr. Chadwick never ceased to have perfect faith in the soundness of the principles on which it was based, and he was indefatigable in defending and establishing it. It has been well said, that "to become popular is an easy thing; but to do unpopular justice,--that requires a Man." And Edwin Chadwick is the man who has never failed in courage to do the right thing, even though it should prove to be the unpopular thing. Whilst burrowing amidst the voluminous evidence on the Poor Laws, Mr. Chadwick never lost sight of his sanitary idea. All his reports were strongly imbued with it. One-fourth of the then existing pauperism was traced by him to the preventible causes of disease. His minute investigations into the condition of the labouring population and of the poorer classes generally, gave him a thorough acquaintance with the physical evils that were preying upon the community, carrying them off by fevers, consumption, and cholera; and the sanitary idea took still firmer possession of his mind. One day, in 1838, while engaged in his official vocation of Secretary to the Poor-Law Commission, an officer of the Whitechapel Union hastily entered the Board-room of the Poor-Law Commission, and, with a troubled countenance, informed the secretary that a terrible fever had broken out round a stagnant pool in Whitechapel; that the people were dying by scores; and that the extreme malignity of the cases gave reason to apprehend that the disease was allied to Asiatic cholera. On hearing this, the Board, at Mr. Chadwick's instance, immediately appointed Drs. Arnott, Kay, and Southwood Smith to investigate the causes of this alarming mortality, and to report generally upon the sanitary condition of London. This inquiry at length ripened into the sanitary inquiry. In the meantime, Mr. Chadwick had been engaged as a member of the Commission, to inquire as to the best means of establishing an efficient constabulary force in England and Wales. The evidence was embodied in a report, as interesting as a novel of Dickens, which afforded a curious insight into the modes of living, the customs and habits, of the lowest classes of the population. When this question had been dismissed, Mr. Chadwick proceeded to devote himself almost exclusively to the great work of his life,--the Sanitary Movement.