Humphrey Lloyd confirmed this man's prediction of 
Humphrey Lloyd confirmed this man's prediction of the existence of conical refraction in biaxial crystals, while his namesake equations are often written in symplectic form. A different equation involves his namesake characteristic function symbolized W, and automatically gives all constants of motion, and is named for this man and Jacobi. His namesake equations calculate the time derivatives of generalized momenta and generalized coordinates.  His namesake variational principle is a general version of the principle of least of action, and states that the time integral of the Lagrangian has a stationary value. For 10 points, name this scientist who discovered quaternions, and whose namesake function is the total energy of a system.
Humphrey Lloyd confirmed this man's prediction of the existence of conical refraction in biaxial crystals, while his namesake equations are often written in symplectic form.