With some of the dry methods, as where middens or cesspits are drained into the sewers, the sewer-water is more offensive than in towns supplied with water-closets. When a midden or cesspool is drained, the principle of conservation, which distinguishes the dry system from the wet, is practically abandoned; and not only so, but the solid matters still remain to be disposed of, by a tedious process. (5) The dry systems, involving the retention of excreta about the house, poison the atmosphere. In all towns where the refuse matters are not removed immediately, there is a high mortality, especially among children. On the other hand, the introduction of the water-carriage system into large towns, with the abolition of midden-heaps and cesspools, has been followed in nearly every case by a diminution in the death-rate, and especially a considerable diminution in that from such diseases as enteric fever. It has furthermore increased the comfort of life, and removed those serious nuisances which are inevitably associated with privies and pail closets, and to a less extent, when care is not exercised, with earth closets. HOUSE REFUSE. In an ordinary household the disposal of ashes from fires, of broken pots and cans, of waste-paper, and of vegetable and animal debris form a serious difficulty. The difficulty is one that can be minimised by the careful housekeeper. Old newspapers, etc., may be sold, though their value is very small; other waste-paper should be burnt. All vegetable and animal debris should be burnt. This may be effected without nuisance if coal-fires are in use, by placing potato-peelings, cabbage leaves and similar substances under the fire until thoroughly dried, and then burning them. The careful housewife will not waste bones, but utilise them for soup. After being boiled they are much less liable to putrefy in the dust-bin; but should even now be burnt in the fire. If this plan be pursued, the contents of the dust-bin will be simply ashes, broken pots and cans, and a few cinders—here again a sifter is desirable—and no nuisance can arise. _It is only organic refuse that smells._ If only gas or paraffin stoves are in use, as during the summer months, any possible nuisance in connection with the dust-bin is minimised by allowing all refuse to dry before it is placed in the dust-bin, or by wrapping all putrefiable substance inside several layers of newspaper. In _emptying the dust-bin or ash pit_, care must be taken that the bottom is thoroughly scraped out. It is well to keep some quicklime (thoroughly dry) for sprinkling on the bottom and sides of the receptacle each time after it is emptied. This greatly helps in keeping it dry and diminishing nuisance during summer.