The term spa is associated with water treatment which is also known as balneotherapy, spa towns or resorts offering such treatment, or the medication or equipment for such treatment. The term thus has various related meanings. The term is derived from the name of the town of Spa, Belgium, where since medieval times illnesses caused by iron deficiency were treated by drinking chalybeate (iron bearing) spring water. In 16th century England the old Roman ideas of medicinal bathing were revived at towns like Bath, and in 1571 William Slingsby who had been to the Belgian town (which he called Spaw) discovered a chalybeate spring in Yorkshire. He built an enclosed well at what became known as Harrogate, the first resort in England for drinking medicinal waters, then in 1596 Dr Timothy Bright called the resort The English Spaw, beginning the use of the word Spa as a generic description rather than as the place name of the Belgian town. At first this term referred specifically to resorts for water drinking rather than bathing, but this distinction was gradually lost and many spas offer external remedies. There are various stories about the origin of the name. A Belgian spring of iron bearing water was called Espa from the Walloon language term for "fountain", and was used in 1326 as a cure by an iron master with such success that he founded a health resort which developed into the town. It is also suggested that the term Espa may be derived from the name of the resort, and that its source could be the Latin word "spagere" meaning to scatter, sprinkle or moisten. It is often suggested, with little evidence, that the word is an acronym of various Latin phrases such as "Salus Per Aquam” or "Sanitas Per Aquam" meaning "health through water", all of which seem to have modern sources.Although such expansions are widely used, they are almost certainly backronyms – words formed from acronyms are very much a twentieth-century phenomenon.