Page 32 - Curriculum Visions Dynamic Book

Using mercury
Mercury oxidizes in air when it is heated strongly, forming mercuric oxide, which is used in mercury batteries. These are small, powerful batteries with a very long life.
Mercurous chloride is popularly known as calomel. It is normally seen as a white powder. Traditionally calomel dust was used as a teething powder for children because it stops the pain of teething. However, it can also poison children, so it is no longer used.
Calomel has also been used as a protection for seedlings. Before planting, seeds were dusted in the powder; afterwards the calomel was puffed along the rows. This was a good way of preventing
club-root pest developing in root crops. However, its use is now restricted because of environmental concerns.
Mercuric chloride is soluble and was, along with arsenic, traditionally used as a poison. In a very dilute form it has
been used to help bring on vomiting and as a diuretic.
In modern use it is made into ointments designed to prevent fungal infections (mercurochrome) and as a disinfectant.
Graphite anodes
 A diagrammatic representation of the mercury cathode or Castner–Kellner cell.
Chlorine
Brine fed in
Spent brine
 Calomel dust was traditionally used to protect seeds from harm before they germinate.
Mercury cathode
Mercury
Pump
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