The lives and welfare of the inhabitants of this vast city are so closely, so inextricably interwoven that, in matters affecting the public health, the action or inaction of one authority may vitally affect the health and the lives, not alone of its neighbours, but even of the people of the city as a whole. Disease and death are no respecters of municipal boundaries, and are not hemmed in or restrained by lines drawn upon maps or recorded in Acts of Parliament. This community of interest of the inhabitants of London was, however, scarcely, if at all, recognised by the general public--it was but seldom the motive to action by the local authorities--but some of the Medical Officers of Health now and then referred to it in their reports. Thus the Medical Officer of Health for Mile-End-Old-Town pointed out (1863) that-- "An untrapped drain, an overcrowded house, an unventilated alley, a rotting dungheap, or a foul closet, may spread disease and sorrow in an entire neighbourhood." And the Medical Officer of Health for Paddington pointed out (1870-1) that-- "The danger of harbouring a contagious disease is not confined to the individual suffering--it is a matter that concerns the community." And the Medical Officer of Health for Whitechapel wrote (1865):-- "Here I would remark, that a uniform system of inspection of all the houses in the several districts in London which are let out in separate tenements should be repeatedly and systematically adopted; for if all the Vestries and local Boards do not act together in this important matter, hotbeds of epidemic diseases will remain undiscovered which will serve as centres from whence such diseases may emanate, and extend over the entire metropolis. The whole population of London, therefore, is interested in the prompt removal of nuisances." Immediately on the passing of the Act some of the Vestries made efforts to deal with overcrowding under the Section which enacted that-- "Any house so overcrowded as to be dangerous or prejudicial to the health of the inmates" is to be considered a "nuisance." That, however, was only a temporary remedy, and affected only overcrowding. Section 35 went to the root of the matter when it insisted that in addition to the prevention of overcrowding, the house in which the people lived should be kept clean and in sanitary condition. "The very foundation of our sanitary structure," wrote the Medical Officer of Health for St. George-the-Martyr, "depends upon the right housing of the poor." The Section 35 was promptly put in force by a few of the Vestries--Chelsea and Hackney being the first to make Regulations and to enforce them.