Epsom salt is not really salt. It is magnesium sulphate — a mineral compound that happens to look like coarse table salt, named after the town in England where it was first drawn from the springs. That distinction matters, because what it does for feet has nothing to do with sodium.
Dissolved in warm water, it does three useful things at once. It draws fluid out of swollen tissue, which is why it helps a puffy ankle after a sprain. It softens hardened skin, which is why it belongs before any attempt at a callus. And it eases the ache in tired muscles and stiff joints, which is why it turns up again and again through this book — for arthritis, for gout, for the swollen feet of late pregnancy.
It is also the cheapest thing in this entire index. A large bag costs less than a sandwich and will last months.
