Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Julius Robert von Mayer (November 25, 1814 March 20, 1878) was a German physician and physicist and one of the founders of thermodynamics. He is best known for enunciating in 1841 one of the original statements of the conservation of energy or what is now known as one of the first versions of the first law of thermodynamics, namely: Energy can be neither created nor de ...