A trial of the Bath Waters: the treatment of lead poisoning.

The Reverend Joseph Glanvill, FRS' was expressing a contemporary view of the aims of the Royal Society when in 1668 he wrote, "We must seek and gather, observe and examine and lay up in bank for the ages to come. This is the business of the experimental philosophers." These words could be applied to the foundation of the Bath General Hospital, which opened in 1741, where it was hoped that by means of a "trial of the waters" it would be possible to show that Bath spa therapy as then practised was effective against many diseases. This was possibly the first extensive trial of any medical therapy. It is commonly assumed that spa therapy has only a placebo effect; that the pleasurable activity of immersion in warm mineral water has social and psychological benefits, but no physiological value. But the records of the Bath Hospital show that Bath spa therapy was an effective treatment for one common and chronic condition, the paralysis that occurs as the result of chronic lead intoxication (colica pictonum). Chronic lead poisoning is a characteristic disorder, presenting with severe abdominal colic and constipation followed by a loss of function of the limbs without loss of sensation. It has been possible, therefore, to use the information collected in the records of the Bath Hospital2 from 1760 to 1879 to identify cases and to show that Bath spa therapy was indeed of value in its treatment.3 During this period of 120 years, 3,377 patients (6.9 per cent of the total admissions) were admitted to the hospital with a diagnosis of paralysis due to lead poisoning; 45.4 per cent of these