Second law of thermodynamics
The second law of thermodynamics may be expressed in many specific ways, the most prominent classical statements being the statement by Rudolf Clausius (1854), the statement by Lord Kelvin (1851), and the statement in axiomatic thermodynamics by Constantin Carathéodory (1909). These statements cast the law in general physical terms citing the impossibility of certain processes. The Clausius and the Kelvin statements have been shown to be equivalent.
Thermodynamics
Pierre Perrot claims that the term "thermodynamics" was coined by James Joule in 1858 to designate the science of relations between heat and power, however, Joule never used that term, but used instead the term "perfect thermo-dynamic engine" in reference to Thomson's 1849 phraseology.