Urine, Butterflies and Moths

How to catch a purple emperor

What can urine be good for? Ask people and the answer would probably be “it’s the body’s waste; it’s no good for anything” (well, had you asked Morarji Desai he would have given you a surprisingly different answer!). Anyway, as a high school student, I used urine and formalin in an experiment that was designed to show how the urea in human piddle can be a basic component of plastics. I enjoyed that experiment and believe children today would also enjoy this bit of chemistry. Anyway I was reminded of that high school experiment in Trinidad, when I met a ”Lepidopterologist” (someone who loves collecting butterflies and moths), who explained to me that the best way to attract certain species was to soak a piece of cloth in human urine and hang it into a tree and wait for some winged “jewels” to arrive.