cat-salt

from Wiktionary, Creative Commons Attribution/Share-Alike License

• n. A sort of finely granulated salt formed out of the bittern or leach brine.

from the GNU version of the Collaborative International Dictionary of English

• n. A sort of salt, finely granulated, formed out of the bittern or leach brine.

from The Century Dictionary and Cyclopedia

• n. A sort of beautifully granulated salt formed from the bittern or leach-brine used for making hard soap.