Emily Dickinson Lexicon

BAY'-SALT, n.

A salt which crystalizes or receives its consistence from the heat of the sun or action of the air. It forms in pits or basins, and from this circumstance receives its denomination. It appears first in a slight incrustation upon the surface of the water, which may be sea water, or any other water in which salt is dissolved. This crust thickens and hardens, till the crystalization is perfected, which takes place in eight, ten, or fifteen days. – Encyc. Chambers.