Although Robert Hooke in 1668 and Ignace Pardies in 1672 had adopted a vibratory hypothesis of light, the conception was a mere floating possibility until Huygens provided it with a sure foundation.
Especially worthy of notice is P. Watrigant's La Genese des exercices de Saint Ignace de Loyola, republished from Les Etudes (loth May, 20th July, 10th October 1897).
But the student may be referred to the modern books Henri Joli's St Ignace de Loyola (Paris, 1899), which is based on the best authorities, and to H.
In the diffusion of this discovery he was much aided by Jacques Ignace Hittorff.
Here he worked at Sault Ste Marie, St Esprit (near the western extremity of Lake Superior) and St Ignace (near Michilimackinac or Mackinaw, on the strait between Huron and Michigan).
He died on his way home to St Ignace on the banks of a small stream (the lesser and older Marquette River) which enters the east side of Lake Michigan in Marquette Bay (May 18, 1675).
A celebrated lawsuit in Alsace, pleaded by his friend and compatriot Ignace Chauffour, aroused his interest by reviving the question of the origin of the feudal laws, and gradually led him to study the formation of those laws and the early growth of the feudal system.