Such is the general rule; and accordingly I would suggest to you that the presence of epidemic cholera, instead of serving to explain away the local inequalities of mortality, does, in fact, only constitute a most important additional testimony to the salubrity or insalubrity of a district, and renders more evident any disparity of condition which may previously have been overlooked. The frightful phenomenon of a periodic pestilence belongs only to defective sanitary arrangements; and, in comparing one local death-rate with another, it is requisite to remember that, in addition to the ordinary redundance of deaths which marks an unhealthy district, there is a tendency from time to time to the recurrence of epidemic pestilence, which visits all unhealthy districts disproportionately, and renders their annual excess of mortality still more egregious and glaring. * * * * * As materials which may aid you to estimate the sanitary defects of the City, I subjoin two tables[14] illustrating the relative mortality of the several sub-districts. The first of these tables indicates numerically the local distribution of the year’s deaths, and gives their proportion to the population of each district and sub-district. The second relates particularly to the last quarter, and illustrates the pressure of the epidemic. The two together furnish a synoptical view of the several rates of mortality, as calculated for the entire City, for the Unions separately, for the sub-districts separately; and for the last quarter of the year separately. In the tedious process of constructing these tables, I have been careful to avoid every source of inaccuracy, and believe that they present you with a true measure of the health of the City during the past year. [14] I have not reprinted these tables quite as here described. The local distribution of the 3763 deaths of the year is given in the Appendix, No. III.; and the sub-district death-rates of the year, as nearly as I can get them, in a note overleaf, page 6. The high mortality of this summer quarter (in which 1395 persons died) will be best appreciated by the reader in referring to Appendix, No. XIV.; where it can be compared with the mortality of similar periods of time in the four other years there accounted for.--J. S., 1854.