Salt

This started when I got a splinter stuck under my thumbnail, and had to soak it in hot salt water. I used a palmful of coarse sea salt and one of my favorite mugs, a heavy stoneware dreadnaught I'd gotten on Martha's Vineyard. When I was done, I set the mug on our sideboard and forgot about it for a week.

The result was startling. Salt water had seeped through cracks in the glaze and into the clay body of the mug. As it dried, the salt was extruded through every crack, in sheets and curls and whiskers. Where the glaze crackling was crosshatched, it formed networks of open-topped boxes.

That was a wake-up call. I've always assumed that if I can't see crackling, the glaze must be intact, more or less. That meant it was a nice smooth inert vitreous surface, so when I cleaned it, whatever I'd had in the mug would be gone.

I was wrong about that. The salt had mapped a network of invisible cracks that covered the mug inside and out, and the underlying clay body was clearly porous. I found myself remembering every warning I'd ever read about not using your working kitchenware for chemical dyeing projects.

I've also been wondering about microbial life. I don't know the size limits on particles that can move through porous stoneware, but viruses are awfully small. Maybe this is why a lot of serious gardeners insist on running their plant pots and jardiniires through a dishwasher with the temperature set on "high" -- basically, an autoclave.

After the mug was completely dry and I'd photographed it for posterity, I took it into the kitchen and gave it a good washing. It promptly grew another coating of salt -- not as luxuriant as the first, but thick enough to be semi-opaque. So I washed it again, and it extruded salt again.

I'm now on my fourth round of salt extrusions. This time, instead of letting the mug dry, I've filled it with fresh water. The idea is that the water will push the salt before it. The results are encouraging: I've got a crop of long elaborate salt whiskers sprouting from the center of the mug handle, which had previously been extrusion-free.

I've always loved pottery. I love it still. But I trust it less.