Bleached rose

A piece of sulfur is ignited in a jam jar. Since a pungent vapor is produced, you should do the experiment out-of-doors. Hold a red rose in the jar. The color of the flower becomes visibly paler until it is white.

When sulfur is burned, sulfur dioxide is formed. As well as its germicidal action in sterilization, the gas has a bleaching effect, and the dye of the flower is destroyed by it. Sulfur dioxide also destroys the chlorophyll of plants, which explains their poor growth in industrial areas, where the gas
pollutes the air.