MAKE pal Rob writes – “Ran across this while looking for something else- it’s from a 1937 Popular Science article on fun with luminous chemistry. Basically, the idea is that one funnel has a solution of luminol and sodium hydroxide in water, and the other funnel has a solution of pottasium ferricyanide and hydrogen peroxide in water. I remember seeing articles about this sort of thing as kid and wishing I could get my hands on some of those chemicals. Doing a quick google, it seems that luminol is used by detectives to detect blood, and you can buy it on the internet. “ [via] – Link.