“Professor” William C. Wilson recognized the difficulties people were having with their hearing and vision, and so produced the Actina Pocket Battery, which purportedly cured both blindness and deafness for a mere ten dollars. In fact, the Actina was simply a small metal cylinder that contained a piece of muslin soaked in sassafras, mustard oil, belladonna extract, ether, and amyl nitrate. The device had to be sent back to the manufacturer three times a year to be “recharged” (for one dollar) and of course, a “caution” was included in the package insert: “Do not allow any one under any circumstances to recharge your Actina. Our formula is a secret..."
The above is from this web site.