Vintage Rexall Puretest Epsom Salt tin originally held 4 ounces of magnesium sulfate. This collectible apothecary item features the classic blue and white Rexall logo along with a 'Laboratory Tested and Approved' seal on the lid. The container displays original typography, directions for use, and a cautionary statement typical of mid-century pharmaceutical packaging. A genuine piece of medical history, this tin shows significant aged character including rust spots and patina, making it an ideal addition to a rustic bathroom display or a vintage advertising collection.