Alphonse Louis Poitevin, French chemical engineer, born in St Calais (Sarthe) in 1820, died in CONFLANS (Sarthe) March 4, 1882. About 1853, Alphonse Poitevin Fox Talbot and realize images probably close to those outlined today, using gum bichromate and colorful.
Poitevin in 1855 obtained the license to print using the technique of potassium dichromate and gives rise to photolithography and carbon print. The same year, he experiences the oléotypie, photolithography, dichromated gelatin (as Fox Talbot also studied): the collotype.