The Meyer lemon is a citrus fruit native to China, thought to be a cross between a true lemon and a mandarin orange or sweet orange. The Meyer lemon was introduced to the United States in 1908 by the agricultural explorer Frank Nicholas Meyer, an employee of the United States Department of Agriculture who collected a sample of the plant on a trip to China. It is commonly grown in China potted as an ornamental plant.
The fruit is yellow and rounder than a true lemon with a slight orange tint when ripe. It has a sweeter, less acidic flavor than the more common grocery store varieties of lemon and has a fragrant edible skin. All lemons are widely known as powerful digestive aids. The combination of high acidity and fiber are effective in cleansing digestion organs.
The white coating or inner rind of a lemon contains the highest vitamin content per volume of most any food. Some studies show that the white coating of a single lemon can contain ten times the amount of Vitamin C as an entire bottle of Vitamin C supplements.
A lemon battery is a device used in experiments proposed in many science textbooks around the world. It is made by inserting two different metallic objects, for example a galvanized nail and a copper coin, into a lemon. The copper coin serves as the positive electrode or cathode and the galvanized nail as the electron-producing negative electrode or anode. These two objects work as electrodes, causing an electrochemical reaction which generates a small potential difference.
In practice, a single lemon battery is incapable of lighting a light bulb. One would need about 500 lemons wired in parallel to light a standard flashlight bulb.