I suppose I could save this for next year's February 14th post, but, nah—it's too much fun to hold back! While transcribing a late 19th C letter from Virginia today, I came across a reference to "Valentine's meat juice." An internet search immediately turned up an Atlas Obscura article on the very thing—turns out to be a tonic made of juices extracted from meat cooked at a low temperature to retain the structure of proteins. Isn't that an excellent detail for historical fiction? Or the little brown, pear-shaped bottles could lend themselves to stories about junk dealers or children inventing magic potions to go in one they'd found. Any other ideas?