He quoted the opinions of eminent scientific men to show that it was possible, under proper methods of burning coal, to lessen the intensity of fogs, and so to lessen materially the causes of ill-health, terminating in fatal disease of those subject to them. In dealing with the wide subject of the "general effect of sanitary conditions upon health," he gave some remarkable facts showing that sanitary work had reduced the death-rate of the European army in India from 60 per 1,000 to 16 per 1,000; that the deaths from tubercular disease in the army at home used to be 10 per 1,000--the sum total now of the total deaths from all causes in a time of peace--a reduction due to the improved hygienic conditions under which soldiers now live; that the death-rate in a certain part of Newcastle (now removed) used to be 54 per 1,000, and of the entire borough 26.1 so lately as seven years ago, while now it was 21.8; that in parts of London, where the people were ill-lodged and crowded, as in parts of Limehouse, Whitechapel, Aldgate, and St. Giles's, the death-rates were 50 per cent. above the death-rates in more open parts of the same districts, and that when proper dwellings were erected the death-rates fell from 50 in the 1,000 to not more than 20 per 1,000. He then spoke of the advantage arising to the health of the population generally by the new dwellings for artisans. He remarked that these improved dwellings "afford accommodation to a population per acre as dense as, and in most cases even denser than, that afforded by the buildings which they replaced. Within limits it is not the density of population which regulates the health. But if a dense population is spread over the surface or close to the surface of the ground, by which means all movement of air is prevented, and if there are numerous corners in which refuse is accumulated, it will be difficult to prevent disease. Dr. Angus Smith's experiments show that while there is less oxygen and more carbonic acid in the eastern and in the more crowded parts of London, yet in open spaces the amount of oxygen rises and the carbonic acid diminishes very considerably; and that we are exposed to distinct currents of good air in the worst, and equally to currents of bad air in the best atmosphere, in towns like Manchester.