It’s Halloween, a day for watching scary movies filled with blood and gore.
In other words, it’s a day to appreciate chemistry.
For roughly a century, entertainers have relied on chemistry to make fake blood look real. In the early 1900s, productions at the Theatre du Grand Guignol in Paris introduced fake blood as an essential prop, according to the American Chemical Society, or ACS.
The French formula for the stage included equal amounts of carmine pigment (which comes from...