In the 1940s, Listerine introduced this popular gadget to broaden its appeal beyond freshening breath.

Eternal flame: Made from durable Lucite, our example still lights up today using its original bulb (though we did change the 80-year-old AA batteries).

“MOTHERS! GET THIS amazing Listerine Throat Light,” urged one advertisement. Listerine promoted its battery-powered device as a tool to “check children’s throat daily [sic],” though it never specified what for. Presumably, even minor redness or irritation was enough to suggest a cold or infection. And since 1940s-era Listerine touted its “amazing ability to fight colds,” any concern became a reason to buy more Listerine. Drugstores bundled the light and rinse for an irresistible 98 cents (about $17 in today’s money; the light and rinse were 75 cents each if bought separately). However, it was simultaneously distributed to dentists and physicians, reinforcing Listerine’s reputation as a scientifically credible and clinically accepted product. Many, like this one, survive today: a reminder how clever marketing made Listerine a mainstay in cuspidors and medicine cabinets worldwide.