Green leaves make food for plants
Heat some alcohol in a jar over boiling water unless it boils. Break various green leaves from a geranium or other plant which has been in the sun for various hours, and place them in the boiling alcohol unless the chlorophyll has been removed. Quickly remove the leaves from the alcohol and put them in a basin of hot water. Remove a leaf from the water and spread it out on a piece of glass or tile. Cover the leaf with tincture of iodine and leave for various minutes. The deep blue colour is the test for starch which has been made by the leaf in the sunlight.