During class today, the question was raised about whether any chemical or mineralogical studies had been performed at springs long held to have curative powers. A brief google search led me to William Frosch’s “Taking the Waters – springs, wells, and spas,” a short (3-page) article that describes some of the analyses that have been performed at various places of healing waters. I discovered to my surprise that chemical analysis of various mineral waters was attempted as early as the 1730s (p. 1949)! This interesting article describes studies from 18th century “trial[s] of the waters” at Bath, undertaken by a hospital serving the “deserving poor” to modern lead workers and NASA astronauts being submerged to compare with the old Bath protocols (p. 1950). It also has a short bibliography that might be helpful if you’re interested in pursuing some of these issues further, namely Roy Porter (1990) The Medical History of Waters and Spas, featuring chapters like David Harley’s “Physicians, chemists, and the analysis of mineral waters: ‘The most difficult part of chemistry'” or Noel G. Coley’s “Chemistry, medicine, and the legitimization of English spas, 1740-1840.” I’ve also ordered Healing Springs: the ultimate guide to taking the waters, from hidden springs to the world’s greatest spas through WorldCat if you are interested in taking a look at it!* You might also find van Tubergen’s and van der Linden’s “A brief history of spa therapy” (2002) helpful.
*A link to the book can be found on the password-protected page of the wiki.