There is an amusing photograph of David Leach looking up from making one of his rounded ‘egg’ pots immediately after he has blown into it. Around his mouth is a ring of clay, in this case porcelain, forming an extra pair of lips. Whether he licked his lips to remove the clay, and hence swallowed it, or wiped his mouth clean is not known, but in the course of their lives potters must, accidentally, ‘eat’ quite a bit of clay. This is quite different from breathing in clay dust, which is not good. The question of whether consuming clay is beneficial has been around for many years. The medicinal qualities of kaolin – as hot poultices for easing boils or as a stomach calmer for jippy tummy – are well known, but there are serious clay eaters who advocate consuming clay for the wider health benefits. This is the topic of a fascinating article in the South African magazine National Ceramics by H Klump, emeritus professor of biochemistry. Quoting pacifist and vegetarian Mahatma Gandhi, who ‘advocated eating dirt to clean your body and relieve constipation’ the article discusses the value/relevance of eating clay.
In a recent gardening programme, the experts were asked whether they would garden with gloves to protect their hands. All were adamant in expressing their belief that no gloves were required except for rough work, and all expressed their belief in the cleanliness of soil. After growing tomatoes in his greenhouse my grandfather used to sterilize the soil to kill off any possible infection, a process that may also have killed off anything useful to human consumption. There is a difference, of course, between clay and soil, the latter containing vast amounts of organic material. I doubt whether eating any old clay can be safely recommended, but despite the crankiness of the concept, maybe the answer does lie in the soil.