Wetness is not a substance but a quality, that seeps and leaks into everything like a stain. Wetness blurs and softens any margins, making distinctions indistinct. When the novelist Richard Jefferies lay on Liddington Hill in Wiltshire, he felt himself pushed up and out of the earth by the solid chalk under his back. The low wet moors of the Somerset Levels, thick with their waters, are the negative of that, the most female of landscapes, and if you lie and sleep there on a summer afternoon you will dream of absorption, of the half-liquid jelly beneath you, shifting in all its ambiguities, curling its flesh around you in the soft kiss of an insect-eating fungus.

If a tractor drives past, the peat will shiver and ripple under you like a belly, wobbling the earth in a slow-motion swell. In the days before tractors, horses that went out on the moor needed sacks around their hooves if they were not to sink into the fields. Others, too sharp-footed – the best Levels horses had feet like frying pans – would quite slowly subside where they stood, their four legs slipping into the peat like the pins of a plug into a socket.

It is as though the grass were no more than a tightened membrane over the body of water. If you sit on the banks of one of the ditches, the high water in the field soaks up into the cloth of your trousers, so that the only thing to do is swim and move over from the watery peat to the peaty water, a half-noticed change from one half-element to another. Simply stand in the shallow margin of the water and let your feet slide down over the warm skin of the peat below you. Slowly the body lowers into the cider-soup, crusty with frog-bit and duckweed, with seeds and reed-shells. The slimed light bodies of the secret eels release a bubble each as they shift away from the strange disturbance. The still water is slick on the skin. Everything hangs there in suspension. Time stops. Your body seen through the whisky water is a golden unnatural brown. You are embedded in the place as though in a tomb, with some strange osmosis of the water sliding into the heart through the skin. It is a soggy, ambivalent fringe world, a world hinged to both and and. A thousand million years ago all life was water-life, and to float in the semi-substance of a summer rhyne is to return to that antiquity.