A "household tip" has been circulating about burning batteries in your fireplace. That was actually published in a 1951 issue of Popular Science magazine. This may have been doable in the '50s, although probably not all that useful. In the 21st century, it could be deadly.
While tossing a modern battery into a fire would likely result in an explosion, a rush of toxic fumes, and possible chemical burns, the advice provided by Popular Science back in 1951 was not nearly so dangerous for its time. As the magazine noted in responding to a reader’s question about burning batteries in fireplaces a decade later, zinc batteries of the early 1950s were typically non-sealed and thus would not build up pressure and explode when exposed to fire:
Modern batteries come in quite a variety, and are more powerful and more dangerous than earlier batteries. Each have their own safety tips, but don't throw any of them in a fire. Ever. -via Boing Boing