Cemeteries can be made upon clay soils, if properly drained by deep cross-drains, and by pipe-drains laid from grave-space to grave-space, duly conducted into the main drain, or by causing the first interments to be made near the drain, strewing gravel at the bottom of each grave opened out, and similarly connecting with this porous layer each new grave with a previous one. When the soil does not admit percolation downwards, it is necessary to get rid of the surface water by laying a line of pipes at the upper end of each row of graves, and so intercepting it. Or upright pipes are placed, reaching down to the bottom of the grave and to the artificially placed gravel then communicating with the drain. The clayey soils of some burial-grounds have also been improved by the admixture of sand and gravel when refilling the graves. But, even after all this expense, the gases evolved during decay are retained very often in the soil, and, after thirty or more years, little or no change will have been effected. The laws of nature are thus contravened; for she has ordained that, in good soil, all but the larger bones shall disappear in twelve years. If interments be made in the worst of clays, sudden heat will open up fissures in the ground with lamentable results. An improperly chosen graveyard, then, may be said to be one where the soil is dense and clayey, and impervious to moisture. It will be insufficiently drained, necessitating the use of planks to walk upon in wet weather. It will be too close to the abodes of the living, too small to permit proper planting, the graves covered, it may be, with flat stones, which prevent the passage downwards of the air and rain, and surrounded, moreover, by high walls which exclude the fresh air. The ground will be stony and insufficiently covered with vegetable soil. No natural outfall will exist, and the drainage-water must be pumped up, the bare idea of which is horrible. It will be near also to water-bearing strata, or to a reservoir. Long before decomposition has taken place, owing to the smallness of the site and the impossibility of obtaining any more land except at high building prices, the organic matter hidden out of sight will be far too large in proportion to the area. From the foregoing we may conclude that a proper site for a cemetery is not everywhere obtainable, and that serious mistakes must often be made. The older burial-grounds can be closed at the expiration of a month's notice given by duly qualified persons, on the order of the Privy Council, and any one assisting at a burial contrary to that order is liable to fine and imprisonment.