“I, the said Joseph Astley, do hereby declare, that the nature of said invention is described in manner following: That is to say, I prepare the salt called muriate of magnesia, or the muriate of alumine, or one or other of the metallic muriates, or any of the combinations of muriate acid from which the acid is capable of being disengaged by heat. What I commonly employ is the muriate of magnesia, which may be procured in different ways, and very easily and economically from the mother liquor of salt-pans, called bittern or salt oil. The other salts contained in this being separated by evaporation and crystallization, I use