They are both known in commerce under the name of “bay-salt,” to distinguish them from the “rock-salt” of the mines.
These beds of rock-salt, when worked to supply salt, are called salt-mines.
By these means this rock-salt lost its water of crystallization and became stronger.
The plains, in the interior, are noted for the production of rock-salt.
"If she ain't been and emptied all the salt-pater into me rock-salt," she cried to one of the other servants who was near.
The brown or rock-salt is dug out of mines, and we went down one of these.
The hills on the island were of rock-salt, from which vases and pedestals for lamps were carved.
A piece of rock-salt left there as well will never be amiss.
rock-salt is found in most parts of the world, in beds of very various ages.
rock-salt is another substance which hinders the passage of the rays.