WHEN THE SAME PLATE IS EXPOSED TO AMMONIA VAPOUR ( 3.8 ), THE SPOTS REAPPEAR WITH A BROWN COLOUR, AND WHEN THE PLATE IS AGAIN EXAMINED UNDER UV LIGHT AT 360 NM A YELLOWISH FLUORESCENCE CAN BE OBSERVED .
EN EXPOSANT ENSUITE LA MEME PLAQUE AUX VAPEURS D'AMMONIAQUE ( 3.8 ), LES TACHES REAPPARAISSENT AVEC UNE COLORATION BRUNE ET, SI L'ON REEXAMINE LA PLAQUE SOUS ULTRAVIOLETS A 360 NM, ON CONSTATE UNE FLUORESCENCE JAUNATRE .