Bloodsuckers: The storied medical history of leeches
(Chemistry professor Joe Schwarcz): What did the jockey who never lost a race whisper into the horse's ear? Roses are red violets are blue Horses that lose are made into glue! OK, so it's a groaner. But until the advent of polyvinyl acetate (PVA) and other synthetic glues in the 20th century, the destiny of aging horses was indeed the glue factory. The collagen extracted from their hides, connective tissues and hoofs made for an ideal wood adhesive. Our word "collagen," for the group of proteins found in these tissues, actually derives from the Greek "kolla" for "glue."
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