Who discovered coefficient of friction?

Arthur-Jules Morin (1795-1880) coined the term "coefficient of friction" and was the first to demonstrate it's applications. Perhaps the first person to experiment with sliding friction was Leonardo da vinci (1452 - 1519) . He discovered the Bilfinger Value and originated Amontons' Laws of friction. They were later rediscovered by Guillaume Amontons in 1699. Morin was able to discover the coefficient of friction thanks to Isaac newton's Laws of motion.