Note that these words and the early attempts at public health legislation, culminating in our great sanitary code, the Public Health Act, 1875, incorporated the tripod on which enlightened public health administration must always be supported, viz., (1) attack on the causes of sickness, (2) satisfactory treatment of the sick, and (3) satisfactory care for the poor. I might properly add (4) attack on the causes of poverty, for it is perhaps the chief merit of the great work of Edwin Chadwick that, in the light of reports on local surveys made by Kay, Southwood Smith, and others, he was convinced and was able to convince Parliament that a very large share of the total destitution then existing was due to the conditions under which the people lived, and the disease generated in these conditions. It is commonly stated that, in the past, public health administration has concerned itself solely with mankind’s environment, failing to recognise the predominant importance of man himself as a transmitter of disease, and of his personal well-being and protection as the point to which energy should be directed. This cannot be said to have been the intention of the legislature or of the earlier reformers; though unhappily this limited view received official acceptance, in large measure owing to the increasing incompatibility between poor-law and public health administration and the spreading over from poor-law to public health administration of the general influence of “deterrence” as a motive of administration. As time went on, this principle came to be realised as contrary to the general interest in anything which concerns the health of the community. _Dirt and Disease_ The crude generalization emerging from the earlier surveys was the close relation between filth conditions and excessive sickness; and the motive behind these inquiries was the desire to remove one of the chief causes of destitution. So late as 1874 Simon said “filth is the deadliest of our present removable causes of disease”; and throughout the whole series of his vividly worded and influential reports, the same fundamentally important teaching was urged. Chadwick’s earlier reports were similarly influenced by the teaching of Dr. Southwood Smith and his collaborators, to the effect that epidemic diseases as a whole are the direct consequence of local insanitary conditions. This generalization, as we now know, needs a modified and more accurate statement, specialized for each individual disease. In its original form, however, it embodied a realisation of the immense importance of the environment to make or to mar individual and national life; it secured the beginning of our national sanitary improvements, and it laid the foundations of the house of health which as nations we are still building.