II: Clay

A look at who's eaten clay and why.

duodi, the 12th of Nivôse, Year CCXXXI
A clay pot in progress. Photo by SwapnIl Dwivedi / Unsplash

Good morning. Today is duodi, the 12th of Nivôse, Year CCXXXI. We celebrate l'argile, soft earth that was made for making.

There's a scientist who claims that life really did spring from clay. Alexander Graham Cairns-Smith wrote a controversial book in CXCIII (1985) that hypothesized clay itself could "learn" how to replicate in an evolutionary manner. Common clay – which is aluminum and silicates glued together with hydrogen and oxygen – has a famous elasticity that can be tougher or slicker depending on the structure of its "plates," or sheet of crystals. Graham Cairns-Smith showed that these plates would "remember" the structure of the material they came from, and do so in a way that was advantageous to habitat spread in, say, stream beds. While he wasn't able to provide a compelling link to how genetic material would then develop, other scientists continue to look into possible clay origins for evolved life.

Nobody knows exactly why people crave dirt sometimes. There have been two main groups associated with geophagia – the mania of desiring to eat soil or clay – and both were living in highly repressive conditions. First, there was an outbreak of geophagia among young European women in the 16th and 17th centuries, and which continued well into Fabre d'Eglantine's days. Secondly, there was a noted tendency for enslaved or famished Africans to engage in the practice.

In current times, there are still regions in South Africa where fine red clay is considered a delicacy, and the propensity for pregnant women to turn to pica has been written about since ancient times, nearly always with an indulgent smirk. But geophagia is still hotly debated. Is it a mental disorder? An atavistic craving for minerals? Something deeper and harder to define?