GOING along one of the back streets of the East End of London on a sultry summer day is by no means a pleasant or refreshing walk. The middle of the street is narrow, and the kennels bordering the side pavements are usually choked up with refuse thrown out from the dwellings on either hand. Heaps of rotting fruit, potato-parings, and decaying cabbage-leaves lie about the causeways, to be eagerly t...