Before leaving the consideration of evils, in which over-density of building and defective ventilation form such important parts, I would avail myself of the opportunity to observe, that it is of incalculable importance to preserve, for the health of the City, every open space which at present exists. The density of buildings within the City of London Union is very great, and in the East and West London Unions, is very considerably greater than in any other part of the metropolis; and not merely are the houses closely packed together, but (as I have already described them) very thickly inhabited. Within the City of London Union, each human being, on an average, has less than an eighth part of the space he would have if residing in the district of Islington; and, small as is this pittance, it is more than double what he would enjoy if he were living in the district of the East and West London Unions. With such density of population, it would, of course, be advantageous if any space now occupied by buildings should hereafter become vacant, so as to increase the breathing-room of the neighbourhood; and your Hon. Court will see the imperative necessity of discountenancing, so far as may be, the erection of additional houses on the few unoccupied spaces which remain. In order to do this effectually, it would be desirable to procure the enactment of a clause, giving you absolute prohibiting power in this respect, whenever, for sanitary reasons, you might think it right to interfere. With respect to those evils which I have set before you, as arising from the unrestricted accumulation of persons of both sexes, and of all ages, within a single sleeping-room--dreadful as they are, I do not consider them irremediable. In the first place, I would beg you to observe, that the very restricted definition of a ‘lodging-house’ given in your Act of Parliament, has hitherto rendered it impossible, in any degree, to regulate dwellings of the description referred to. An amendment of that definition might bring them within your control, and might enable you, not only in these instances, but in many others, to restrict the numbers of inmates, to compel the removal of persons with infectious disease, and to enforce provisions of decency, cleanliness, and ventilation.