1824. Niépce obtained pictures in the camera-obscura upon metal plates coated with asphaltum, or bitumen of Judea.
— L. G. M. Daguerre commenced his researches.
— Permanganate of potash. Fromenkerz.
1826. Bromine discovered in sea-water by M. Balard.
— Bromine of silver made.
1827. Niépce exhibited his pictures in England, and left one or more, now in the British Museum.
1829. Niépce and Daguerre entered into an alliance to pursue their researches mutually.
1832. Evidence of Daguerre employing iodine.
1837. Rev. J. B. Reade, of Clapham, London, obtained a photograph in the solar microscope, and employed tannin as an accelerator and hyposulphite of soda as a fixer for the first time in photography.
1838. Reflecting stereoscope exhibited by Charles Wheatstone.