In onion there are molecules that contain one or more of sulfur atoms: the organic sulphides. When cutting the onion these sulphides are combined with another substance present in different layers, “the allinasi enzyme”, which degrades amino acids and volatile odorless. These amino acids, reacting with water covering the cornea, are transformed into acids, mainly sulfuric and sulphide. As corrosive substances, the eye tries to rid activating the lacrimal glands. From the’90 in different parts of the world  , it attracts the attention of scientists, agronomists and geneticists. How it is possible to avoid tearing ? . In a research to assess the volatile components in some onion cultivars an investigator at the University of Naples, Giancarlo Barbieri, showed 46 volatile compounds, including many sulfur compounds, aldehydes and some alcohol. They noted differences between varieties of yellow and white tunic. For example, the level of volatile compounds in cultivar Density is about twice that in pure Blanco and Reddy. The cultivar late or have a Serb acid content Pyruvic twice as sweet. E ‘result that even the mineral sulphate fertilizer can help improve the level of alcohol pungency, especially in the case of onions. A researcher of Georgia has shown experimentally that after the administration of calcium sulfate to the soil concentration of acid in Pyruvic bulbs has doubled.