It is called Citrius Limon in Latin and grown in subtropical regions.
They are small trees carrying volatile oil. Fruits of lemon are used as food, furthermore, fruit rinds, flowers and leaves are used as aromatic oil for giving smell and taste.
A substance which is called Pectin is obtained from white part at the bottom of rind. This substance is used in stopping diarrhea in medicine and production of jam, jelly, ice-cream in food industry, its oil is obtained by method of distillation or cold pressing.
Lemon oil which is produced by cold pressing is generally used against mouth, gum, pharynx and tonsil, bronchitis, concentration weakness, influenza, cough, sinking, fatigue and immune weakness in aromatherapy.
In addition, lemon oil has an effect to clean skin, decrease acne, rash, distension and cellulite. Filter spreads microbe and bacteria while sweeping the house. Thus, if you drip 3-5 drops of essence on the filter, it kills microbes.