He was 26 years old when he published On the Conservation of Force in 1847 whose ideas were more precise than Mayer's and more wide-ranging than Joule's. In 1850 he developed 
He was 26 years old when he published On the Conservation of Force in 1847 whose ideas were more precise than Mayer's and more wide-ranging than Joule's. In 1850 he developed an ophthalmoscope for viewing the human retina. He also argued that the cochlea resonates at different frequencies and analyses complex sounds. Later in life he gave up physiology for medicine and became interested in Maxwell's work on electromagnetic radiation. His pupils included Hertz, Boltzmann, and Michelson. FTP name this German physicist and physiologist, the namesake of a kind of free energy.
He was 26 years old when he published On the Conservation of Force in 1847 whose ideas were more precise than Mayer's and more wide-ranging than Joule's.
Hermann von Helmholtz