[Sidenote: Allahabad.] At the Government Farm at Allahabad (United Provinces) the system known as the Allahabad Shallow Trench was in successful operation, and provided for the whole of the cantonment and half the municipal population; there is an unlimited area of land available, the soil being of various kinds, black cotton, sandy loam and stiff clay. The only crops grown are grass and sorghum, and it is found that the manurial value of the night-soil is not exhausted for three or four years. Trenching can, however, be done every third year on the same land without making it “sewage sick;” land which was worth Rs. 2 will, after trenching, fetch about Rs. 10 per bigha for seven or eight years. At Meerut for the year 1911–12 the sale-proceeds of night-soil and city sweepings amounted to Rs. 12,871, and at Furrakhabad _cum_ Fatehgarh to Rs. 18,317. [Sidenote: Allahabad Shallow Trench System.] The area required for the contents of a 60–gallon conservancy cart is 80 sq. ft., the most suitable dimensions being 16 feet long by 5 feet wide; 3 inches of the top surface of this space is removed and placed on the embankments of the plot near which the first line of trenches is dug; the subsoil thus exposed is then well cultivated and pulverized to a depth of 9 inches, when the contents of the cart are tipped into the centre of the trench; the liquid matter rapidly sinking into the loosened soil, while the solid excreta remains on the top in a layer less than ⅛ inch in thickness; 3 inches of earth are then similarly removed from the next trench which is parallel to the first, no intervening space being left, and thrown over the night-soil in the latter. The practical working is very simple, as all that has to be done, is to see that a sufficient number of trenches for the daily supply are dug the day before and the earth from them placed over the filled ones. It has been found from experience that night-soil, thus treated, decomposes in less than a week and, if dug then, no trace is observable; the effluvium disappears after three days, and crops are successfully grown immediately after trenching. The Shallow Trench System is by far the most scientific one, but requires a large area of land, working out to 545 sixty-gallon carts per acre. At Muzaffarpur during 1912–13, part of the night-soil was sold for Rs. 1,200, and part of it trenched in the municipal trenching ground, which was leased out for Rs. 1,045. The practical objection to this system is the fly pest. It is therefore only applicable where the trenching grounds are remote, and to the leeward side of the town. Sprinkling chloride of lime or quicklime on the top of the trenches prevents the breeding of flies. The researches of Majors Firth and Horrocks, R.A.M.C., published in the _British Medical Journal_, however, show that the enteric bacilli is capable of surviving in soil for much longer periods than has been believed possible. These can exist apparently in ordinary soil for 65