The poor population of New York is to-day but an immense army in camp, upon small territory, crowded into old filthy dwellings, and without the slightest police regulation for cleanliness. If this army should abandon its camp and begin a roving life in the country, all the diseases now prevalent would disappear. And it must be added, that if these deserted and uncleaned tenements should immediately be filled by healthy people from the country, the new tenants would at once begin to suffer from all the pestilential diseases now indigenous to that part of the city. I have now laid before you, as briefly as possible, the accumulated evidence that New York is to-day full to repletion with all the causes which originate and intensify the most loathsome and fatal diseases known to mankind. This evidence proves that at least half a million of its population are literally submerged in filth, and half-stifled in an atmosphere charged with all the elements of death. I have demonstrated that the legitimate fruits of her sanitary evils is an excessively high death-rate and a correspondingly large sickness rate. [Sidenote: Can the Causes of Disease Be Removed?] The all-important question which now concerns us as citizens, and you as practical legislators, is, can these evils be remedied? We answer, yes. In the first place the streets can be kept clean. Other cities accomplish this object, and therefore New York can, and we have striking illustrative examples. In certain portions of the city the streets are as clean as this floor. They are swept daily, and scarcely a particle of dust is left in the streets or gutters the year round. But they are cleaned by private contract of the people residing upon them. What individual enterprise can do for whole squares, surely a corporation so lavish in money as New York ought to be able to do for the city at large. The courts, alleys, cesspools, and privies can be cleansed and kept in good condition. There are tenant-houses which are as clean in all their alleys, courts, and cellars as the best-kept private houses. These are dwellings for the poor in which the landlord takes especial interest. What is done for the surroundings of one of these houses, may be done for all. But the tenant-houses of the worst class may be quickly placed in a good sanitary condition. [Sidenote: Improvements During the Inspection] The inspectors furnish many examples of this fact. They were frequently mistaken in their inspection for an official, and when their visit to the tenant-houses was reported to the landlord, he hastened to renovate the building. Some of the most filthy quarters were so completely changed within forty-eight hours that the inspectors could scarcely recognize the locality. The Inspector of the Eighth Ward says: