Thus then our position stands. Scientific prediction of phenomena can arise only in the knowledge of laws. That the phenomena of this disease, however capricious they may seem, are obedient to some absolute uniformity as yet beyond our ken--are enchained by that same rigid sequence of cause and effect which is imposed on all remaining Nature--it would be impossible to doubt. But these conditions are hitherto unknown to science. Hitherto we can speak of the facts alone, with a short empirical knowledge of their succession. Yet in this light, such as it is, the conclusion is only too obvious. If the disease, already notorious for a tendency to return on its former vestiges, repeat on this third occasion the steps of its two previous courses; or, perhaps I should rather say, if it now proceed consistently to complete a repetition which it has already half-effected; Asiatic Cholera will be severely epidemic in London in the third quarter of next year--will proceed, with a stern unflattering test, to measure the degree in which those promises of sanitary improvement have been redeemed, which the terror of its recent visitation extorted even from the supinest and most ignorant of its witnesses. In the face of so great a danger, you will reasonably claim of your Officer of Health that he shall report to you, how far the City is already fortified against this dreadful invasion--how far the hygienic defences of life, if weak, may be strengthened--how far there remain breaches now insusceptible of repair. * * * * * 1. It forms an all-important part of these considerations for resistance to the disease, to recognise quite accurately what is its fashion of attack. Since I last addressed you on the subject, in my Report for 1849-50, the materials for correct generalisation have been very largely increased by Dr. Farr’s admirable Report to the Registrar-General on the Cholera in England, and by numerous other important publications. By collating with these works the more restricted, yet not uninstructive, experience which arose within your particular jurisdiction, I hope to have enlarged my knowledge of the subject, and to have become able with greater confidence to submit my conclusions for your acceptance. The first and most obvious characteristic of the disease is its preference for particular localities. It is eminently a district-disease. And the conditions which determine its local settlement are demonstrable physical peculiarities. After carefully reviewing the subject, I do not know that I need qualify, except to express more confidently, the account I formerly gave you of those peculiarities, as consisting in the conjunction of dampness with organic decomposition.