Rene Descartes was a key figure in the scientific revolution and had some stuff to do with math so probably him ( don't hold me to that and check other peoples answers)
René Descartes was a french philosopher and mathematician in the 17th century. He is known for his effort to spread western knowledge in the Scientific Revolution. His work in the field of mathematics is recognized where he used algebra to describe geometry ( x and y axis ) which came to be known as the Cartesian Coordinates system.
One trick to avoid the plague was an early form of aromatherapy. Doctors told patients to carry flowers on their bodies thinking that the odor would keep the plague at bay.