The postage rate for a letter in 1693 was determined through how much light could pass through the letter. The postage rate would be more expensive if less light went through, and this process was called candling.

The molecular structure of DNA was first determined by Watson and Crick in 1953.

To "testify" was based on men in the Roman court swearing to a statement made by swearing on their testicles.

AMAZING FACTS