Source : Webster's Revised Unabridged Dictionary (1913)

Niepce's process \Niep"ce's proc"ess\ (Photog.)
   A process, now no longer used, invented by J. N. Niepce, a
   French chemist, in 1829. It depends upon the action of light
   in rendering a thin layer of bitumen, with which the plate is
   coated, insoluble.