Children's Books & Cocaine

During World War II, almost the entire Jewish population of Denmark was smuggled across the sea to Sweden.
"After the Nazis began to use police dogs to sniff out hidden passengers on the fishing boats, Swedish scientists worked swiftly to prevent such detection. They created a powerful powder composed of dried rabbit's blood & cocaine; the blood attracted the dogs, and when they sniffed at it, the cocaine numbed their noses and temporarily destroyed their sense of smell. Almost every boat captain used such a permeated handkerchief, and many lives were saved."

Fantastic book, by the way.