Millions of people all over the world have asked for Epsom salts, and used it with recognisable effect, without knowing anything about Epsom.

The name was first used, as far as is known, by Nehemiah Grew in 1695. He lists other wells around London, including Barnet, Acton, Dulwich and Streatham, where the water was of the same nature as Epsom. He was granted a Royal patent for "The Way of Makeing the Salt of the Purging Waters perfectly fine...very cheape". But though Epsom gave its name to the water, the quantities available from the Epsom wells were relatively small.

The reasons for the efficacious action of Epsom salts were not known until a long time after its discovery, and magnesium as an element was not discovered until nearly a century later. Medical knowledge was, of course, very much less at that time, so there was correspondingly more scope for waters becoming known for their curative powers. People travelled long distances in the hope that they would be cured of their ills. Some mineral waters were supposed to cure almost everything one can imagine, and, whatever one's ailment, a cure for it could be bought from the chemist.

The first record of the Epsom Well, though it was already famous then, is in an account of 1629 by 2 Dutch diplomats who set out from London on horseback "to see some Royal Castles and Ipson Wells". (incidentally, this account was first published in Holland in 1942!). Lord North, in 1637, claims to have been the first to have told the King's people of the use of Tonbridge and Epsom waters for health and cure, and added that it was a lot cheaper than travelling to Spa on the Continent.

Epsom Salt is made from a rock substance called Dolomite, which is found abundantly in, and derives its name from, a mountainous district in the South Tyrolean Alps called The Dolomites'. When examined by the chemists, this Dolomite rock is found to belong to a very large group of substances known as 'salts', in which an alkaline base is combined with an acid radical to form a neutral substance the
'salt'. It consist of two metals, calcium and magnesium, combined with two non-metallic elements, carbon and oxygen, and takes the form of a neutral double salt know as carbonate of calcium and magnesium.