[Footnote 10: They had "health wardens" in the old days, and the Council of Hygiene tells of the efficient way two of them fought the smallpox. One stood at the foot of the stairs and yelled to those minding a patient in the next story to "put pieces of camphor about the clothes of the sick and occasionally throw a piece on the hot stove." The other summoned the occupants of a smallpox smitten tenement to the hall door and cautioned them to say nothing about it to any one, or he would send them all to the pest-house!] The tenement had grown its logical crop. In the sweating conspiracy it is a prime factor. Its extortionate rates make the need, and the need of the poor was ever the opportunity of their oppressor. What they have to take becomes the standard of all the rest. Sweating is only a modern name for it. The cause is as old as the slum itself. [Illustration: Jersey Street Rookeries.] However, the new light was not without its allies. Chief among them was the onward march of business that wiped out many a foul spot which had sorely, tried the patience of us all. A carriage factory took the place of the Big Flat when it had become a disgusting scandal. Jersey Street, a short block between Mulberry and Crosby streets, to which no Whitechapel slum could hold a candle, became a factory-street. No one lives there now. The last who did was murdered by the gang that grew as naturally out of its wickedness as a toadstool grows on a rotten log. He kept the saloon on the corner of Crosby Street. Saloon and tenements are gone together. Where they were are rows of factories, empty and silent at night. A man may go safely there now at any hour. I should not have advised strangers to try that when it was at its worst, though Police Headquarters was but a block away. [Illustration: The Survival of the Unfittest.] I photographed that phase of the battle with the slum just before they shut in the last tenement in the block with a factory building in its rear. It stood for a while after that down in a deep sort of pocket with not enough light struggling down on the brightest of days to make out anything clearly in the rooms,--truly a survival of the unfittest; but the tenants stayed. They had access through a hallway on Crosby Street; they had never been used to a yard; as for the darkness, that they had always been used to. They were "manured to the soil," in the words of Mrs. Partington. But at length business claimed the last foot of the block, and peace came to it and to us.