It has been already incidentally stated that the recent epidemic of Cholera committed its most severe ravages on the south side of the river. This fact, as well as the relation which the other districts of the metropolis bear to each other, will be seen in the following table, in which the mortality in the several districts of London is given for the two epidemics. The districts are placed in the order of their mortality, beginning with that which suffered most severely. The deaths in the late epidemic are those registered from October 7, 1848, to November 3, 1849. This table shows a difference between the two epidemics which is worthy of note, namely, that while in the first epidemic the central districts suffered more severely in proportion than the east districts, the order has been reversed in the recent epidemic. In other respects it will be seen, that the mortality of the several districts coincides. The cause of this difference may, perhaps, be found in the great improvements which have taken place in the central districts during the last twenty years, especially in and about the parish of St. Giles. On comparing the mortality from Cholera in the several districts during the recent epidemic, it will be seen that the deaths in the low-lying districts on the south side of the river have been, relatively to the population, nearly twice as numerous as in the east districts, nearly three times as numerous as in the central districts, nearly four times as many as in the west districts, and nearly six times as numerous as in the north districts. If we throw all the districts on the north side of the river together, we obtain a mortality of about 1 in 280, which is, as nearly as possible, a third of that prevailing on the south side. The column which gives the mortality of females from all causes, proves that the mortality from Cholera does not submit itself to the same rules, whatever they may be, which govern the ordinary mortality. From the Cholera as it prevailed in the several districts of London, let us now proceed to determine its mortality in the subdistricts into which they are divided; and here, as in the foregoing * See the Fifth Report of the Registrar-General. table, let us compare, where we have the means of so doing, the two epidemics of 1832 and 1848-9. This is done in the following table, in which the several sub-districts are arranged in the order of their mortality in 1848-9, beginning with that in which the greatest relative number of deaths from Cholera took place. This table exhibits, for the several sub-districts, similar results to those just obtained for the five principal groups. There is only a general correspondence between the localities in which the two epidemics have proved most and least fatal, and in which the mortality from all causes is highest and lowest. The districts least and most severely visited by Cholera are, with few exceptions, grouped towards the two extremities of the table; but the mortality from all causes refuses to be brought into subjection to the rule of the prevalence of Cholera, the most and least healthy districts being blended in every part of the table with great irregularity. In searching for a local explanation of the variable fatality of Cholera in different parts of London, that which appears most feasible, is elevation. The outbreak of Cholera in the low swamps of India in 1817; and its marked preference, as a general rule, for sea and river ports, for towns, like Salisbury, situated amidst marshes, and for low-lying situations on the borders of rivers or water-courses, point strongly in this direction. The great fatality of the Cholera on the south side of the river, and the especial severity with which it visited Rotherhithe and Bermondsey, so notorious for their filthy ditches, and equally filthy habitations, go far to confirm this explanation. A table given by the registrar-general, showing the deaths from Cholera for every 10,000 inhabitants in each aistrict in London, in the 52 weeks ending September 29, 1849, supplies the means of testing this probability. From it we have compiled the following table : · Rotherhithe, Bermondsey, St. George, St. Saviour, St. Olave, Lambeth, Cam-1 ........ Wandsworth, West London, White- 20 to 30 feet chapel, and Lewisham above. Bethnal-green, City, St. Martin-inthe-Fields, and St. George, Hanover Square.. St. Luke, Shoreditch, St. James, East Hackney and Holborn 35 26 30 above. 60 to 70 feet St. Giles and Clerkenwell... above. St. Pancras, Islington, Marylebone, and Upwards of 70 * District of Wandsworth, comprising Mr. Drouet's establishment at Tooting. These comparisons certainly favour the conclusion, that the most fatal Cholera is in low situations; but it is obvious that the influence of elevation is modified by many concurrent predisposing and exciting causes. Thus, if we select three districts, Rotherhithe, Bermondsey, and St. George's, Southwark, each of which has the same mean elevation as the river itself at high water, we find the mortality to be respectively 263, 189, and 164, in the 10,000; but that which constitutes the main difference between these three districts, namely, the proximity to the Thames, and the consequent easy access of sailors from infected ships, probably offers a sufficient explanation of the different rates of mortality Rotherhithe, which is most accessible, and a common resort of seafaring men, suffers the greatest mortality, while St. George's, Southwark, which is least liable to the intrusion of this class of the population, exhibits the lowest rate. Bermondsey is intermediate in both respects. To take another instance :-Wandsworth and Lewisham, both on the south side of the river, have an elevation, the one of 22 feet, the other of 28 feet, above high-water mark; but Wandsworth lost 108 in the 10,000, while Lewisham lost only 35 in the 10,000; but a great part of the excess in the Wandsworth district is at once accounted for by the awful loss of life in Mr. Drouet's establishment at Tooting, a loss evidently due to causes existing within the establishment itself. Allowance being made for this accidental circumstance, the mortality is at once reduced to 76 in the 10,000, which would doubtless be still further diminished by the omission of the frightful mortality in Albion Terrace, due also to causes unconnected with mere elevation. The advantage of six feet of elevation added to that of less density of population, will probably go far to account for the disparity still existing. Density of population will perhaps be found to account, at least in part, for the difference of mortality in other districts, having the same degree of elevation. Three such districts are Whitechapel and West London on the north, and Lewisham on the south side of the river, all of which are twenty-eight feet above the Thames at high water. The mortality of Whitechapel is 67 per 10,000, and that of West London 79 per 10,000, while that of Lewisham is only 35 per 10,000, or less than half the average of the other two districts. This difference coincides with, if it do not depend upon, the great density of the population in the first-named districts, when compared with the last. On the other hand, there are districts of equal elevation which differ comparatively little in density of population, and which, nevertheless, have suffered in a very different degree from the ravages of Cholera. The adjoining districts of St. Luke and Shoreditch, for instance, have each the same elevation of 48 feet above the Thames at high water, and yet St. Luke's has lost by Cholera 48 in the 10,000, while Shoreditch has lost 71. St. Luke's, which suffered least, has a density of population represented by 23 square yards to each person, while Shoreditch has a density represented by 36 square yards to each person. A still greater difference in the mortality from Cholera in two districts having nearly the same elevation, exists in the case of St. Giles-in-the-Fields and Clerkenwell, of which the first has an average elevation of 68 feet, and the last of 63 feet. The mortality from Cholera in St. Giles was 51 in the 10,000, while in Clerkenwell it was only 18 in the 10,000, and yet the density of the population differs but little in the two cases, the parish of St. Giles giving 22 square yards to each person, and that of Clerkenwell 27. As it is natural to suppose that density of population is one of the elements which regulates the mortality from Cholera, let us now inquire in what degree this influential cause of disease has influenced the spread of the pestilence. The district which has suffered most severely by Cholera is Rotherhithe, which lost 263 in the 10,000, and yet the density of its population is represented by the favourable figure of 240 square yards to each person. Again, the Strand and Holborn presents the very favourable rate of mortality of 35 in the 10,000, and yet the population in the one has a density represented by 18 square yards, and in the other by 20 square yards to each person. Another way of testing the influence of density of population on the mortality from Cholera, will be to compare districts having the same density of population. We find two such districts in St. Martin's-in-the-Fields and Bethnal Green. Each has a density of population represented by 50 square yards to each person, and yet the mortality from Cholera in the one has been 33, and in the other 91 in the 10,000. We may bring the question to one other test; the density of population in Shoreditch is just double that in Westminster, and yet the mortality of the former was 71, and of the latter 69 in the 10,000. From all the comparisons which we have just instituted, the conclusion seems justified that elevation exercises a greater influence upon Cholera than density of population. Perhaps few facts are better established in reference to the Cholera than its fatality in low-lying districts upon the banks of rivers; but no argument is necessary to prove that that increased mortality is not dependent on the mere elevation, but on the defective drainage, and consequent dampness and impurity of the air, which, in the present condition of our towns, are apt to prevail in such low situations. The dreadful ravages committed by Cholera in the elevated but filthy districts of Bilston and Merthyr Tydvil, are strongly confirmatory of this view of the case. Merthyr, which is 500 feet above the level of the sea, and, according to Sir H. T. de la Beche, in an open, airy, and well-exposed situation, shares with Sculcoates, on the level of the Humber, a mortality (mainly due to Cholera) at the rate of upwards of 10 per cent. per annum. Having examined the influence of elevation and density of population, separately, on the mortality from Cholera, it will be interesting to inquire into the relation of the two causes combined to the prevalence and mortality of that disease. This may be best done by taking two districts having the same, or nearly the same, density, and the same, or nearly the same, elevation. The two districts of |