thirteen and fourteen times as fatal to the population having the impure water as to that having the improved supply. It is particularly worthy of remark that, during the four weeks of the epidemic we are now considering, there were but 563 deaths from cholera in the whole metropolis, of which 286, or more than one-half, occurred amongst the customers of the Southwark and Vauxhall Company, who comprise a little more than one-tenth of London, and a considerable number of the remaining deaths took place amongst mariners, and others employed amongst the shipping, who almost invariably draw their drinking water directly from the river; it is, therefore, evident that at this early period of the epidemic the impure water of the Thames was almost the exclusive means of the propagation of the malady. In the next three weeks of the epidemic there were 1,180 deaths from cholera in the districts supplied by the two water companies. Of these, the fatal attack took place in 977 cases in houses supplied by the Southwark and Vauxhall Company; in 84 cases in houses supplied by the Lambeth company; in 101 instances the supply was from some other source; and in 18 cases it could not be ascertained, for reasons previously stated. Taking into account the population supplied respectively by each company, the mortality was, at this period of the epidemic, nearly eight times as great in that supplied by the Southwark and Vauxhall Company as in that supplied by the Lambeth Company. During the last ten weeks of the epidemic, from August 27th to November 4th inclusive, 3,564 deaths occurred in the districts to which the supply of the two water companies extends, and the returns of the district registrars showed that in 2,443 cases the water supply of the house in which the fatal attack took place was that of the Southwark and Vauxhall Company; in 313 cases it was that of the Lambeth Company; in 207 instances the supply was from pump wells and other sources independent of the two water companies, and in 601 instances the supply was not ascertained.[4] These numbers show a mortality of 916 to each 100,000 inhabitants supplied by the Southwark and Vauxhall Company, and 180 to each 100,000 supplied by the Lambeth Company; consequently, at this period of the epidemic, the mortality was still more than five times as great amongst the population supplied by the former company as amongst that supplied by the latter.