This innocent little green stamp from Kashmir in 1867 was printed with an ink made from “Paris Green” a highly toxic compound. Also known as Schweinfurt green, Emerald or Vienna green. It is a highly toxic emerald-green crystalline powder that has been used as a rodenticide and insecticide and also as a pigment, despite its toxicity. It got it’s name by being used to kill rats in the sewer in Paris.