His greatest discovery was popularized by the Dutch scientist who experimentally confirmed it, Hendrik Roozeboom.  
A paper he wrote about the geometrical representation of a certain kind of property by means of surfaces so excited Maxwell that he made a model illustrating the method.  During the early 1880s, this man worked on a modification of the quaternion which he thought could be adapted into a new system of vector analysis, but it had little impact.  He developed an "electrical theory of light" which presumed that light is a disturbance propagating through relatively fine-grained media, while his last work was a treatise on Elementary Principles in Statistical Mechanics which he completed a year before his death in 1903.  His greatest discovery was popularized by the Dutch scientist who experimentally confirmed it, Hendrik Roozeboom.  His most famous work was translated by Le Chatelier and Ostwald, and established a basis for the theory of the thermodynamic properties of heterogenous substances.  FTP, name this founder of physical chemistry, an American scientist known for his namesake phase rule.
A paper he wrote about the geometrical representation of a certain kind of property by means of surfaces so excited Maxwell that he made a model illustrating the method.  
Josiah Willard Gibbs