These plans for the removal of excreta do not deal with the equally important refuse liquid--viz., the waste water from washing and stables, etc. As it is necessary to have drains for the purpose of removing the waste water, it is more economical to allow this waste water to carry away the excreta. In any case, you must have drains for removing the fouled water. Down these drains it is evident that much of the liquid excreta will be poured, and thus you must take precautions to prevent the gases of decomposition which the drains are liable to contain from passing into your houses. There is a method which you might find useful on a small scale to which I will now draw your attention, as it is applicable to detached houses or small barracks--viz., the plan of applying the domestic water to land through underground drains, or what is called subsoil irrigation. This system affords peculiar facilities for disposing of sewage matter without nuisance. There are many cases where open irrigation in close contiguity to mansions or dwellings might be exceedingly objectionable, and in such cases subsoil irrigation supplies a means of dealing with a very difficult question. This system was applied some years ago by Mr. Waring in Newport, in the United States. It has recently been introduced into this country. The system is briefly as follows: The water from the house is carried through a water-tight drain to the ground where the irrigation is to be applied. It is there passed through ordinary drain pipes, placed 1 ft. below the surface, with open joints, by means of which it percolates into the soil. Land drains, 4 ft. deep, should be laid intermediately between the subsoil drains to remove the water from the soil. The difficulty of subsoil irrigation is to prevent deposit, which chokes the drains; and if the foul domestic water is allowed to trickle through the drains as it passes away from the house it soon chokes the drains. It is, therefore, necessary to pass it in flushes through the drains, and this can be best managed by running the water from the house into one of Field's automatic flush tanks, which runs off in a body when full.