Monsieur Leroy (Saturnin Fabre) is a wealthy businessman who made his fortune in shoe polish :"l'éclat ,c'est moi" (=shine is mine) ;his son ,Jules (Jean Tissier),in a grown up kid, a good for nothing whose main activity is to collect the shoes.One of the workers ,Hyacinthe Camusset (Carette), is fired,but much to the horror of the ruthless boss , he is actually the heir , the real owner of the shoe polish plant ; he won't survive this fatal discovery .Jules becomes the boss and tries to do away with Camusset : he gives him a promotion , nominates him to the post of laboratory manager ,for there are lots of explosions there ; in desperation ,he tries to marry him to his sister ,but ,alas ,she's in love with an engineer ....Riotously funny , mainly in its first part, "le merle blanc" is good fun ; nothing heady ,nothing intellectual,but lines which hit home ,a fabulous threesome :Fabre/Tissier /Carette ,and inventive situations ,even including a manor and its family ghost.