While treating of the manner in which noxious emanations are conveyed to a distance, and are enabled to diffuse their influence over a whole town, instead of concentrating it in some single slaughter-house or burial-ground, I indirectly suggested what I have now to illustrate; that all the evils of all the nuisances in existence acquire their utmost local intensity of action when the diffusion of their gaseous products is interfered with, and when, from absence of ventilation, these are retained in the immediate vicinity of their source. The inhabitants of open streets can hardly conceive the complicated turnings, the narrow inlets, the close parallels of houses, and the high barriers of light and air, which are the common characteristics of our courts and alleys, and which give an additional noxiousness even to their cesspools and their filth. There are very few who, without personal verification, would credit an account that might be given of the worst of such dwelling-places. Let any one, however, who would do full justice to this frightful subject, visit the courts about Bishopsgate, Aldgate, and the upper portion of Cripplegate, which present some of the worst, though by no means the only instances of pestilential residence. A man of ordinary dimensions almost hesitates, lest he should immovably wedge himself, with whomsoever he may meet, in the low and narrow crevice which is called the entrance to some such court or alley; and, having passed that ordeal, he finds himself as in a well, with little light, with less ventilation, amid a dense population of human beings, with an atmosphere hardly respirable from its closeness and pollution. The stranger, during his visit, feels his breathing constrained, as though he were in a diving-bell; and experiences afterwards a sensible and immediate relief as he emerges again into the comparatively open street. Now, I am prepared to show that there are many, very many, courts within the City, to which the above description accurately applies; courts and alleys hemmed in on all sides by higher houses; having no possibility of any current of air; and (worst of all) sometimes so constructed back to back, as to forbid the advantage of double windows or back doors, and thus to render the house as perfectly a _cul-de-sac_ out of the court, as the court is a _cul-de-sac_ out of the next thoroughfare. * * * * * It is surely superfluous to observe, that these local conditions are utterly incompatible with health. Among their dense population, it is rare to see any other appearance than that of squalid sickness and misery; and the children, who are reproduced with the fertility of a rabbit-warren, perish in early infancy. In the worst localities probably not more than half the children born survive their fifth year, and of the 3763 deaths registered last year in the City of London generally, 1410 were at or under seven years of age.