The medical baths of the Romans were of Greek origin. They were based on a combination of Aristotle’s basic terrestrial elements; earth, wind, fire and water, in hot saline and gaseous waters.

Health Spas had grown up around such springs, to which the sick made pilgrimages to regain health. Greek natural healers debated the origins behind the healing effects, but it wasn’t until after the Roman period in the 16th century that the medical properties once again came under analysis.

The waters were said to contain a ‘secret life-giving acid’, called “acidum occultum”. But the acid was actually carbonic acid, and the more the waters contained, the healthier and more revitalising they were considered to be.

The importance of carbon dioxide in connection with health spas is a subject still under discussion today. It has been said that during a 20-minute carbon dioxide bath, the body absorbs about 6 litres (12 grams) of gas. The carbon dioxide content regulates the rate of breathing, therefore allowing it to be stimulated. Carbonic acid also reduces the loss of body heat by the absorbsion of small gas blisters that are deposited under the skin. Depending on concentration levels, certain mineral waters can regulate the osmotic pressure and in this way affect the function of certain body organs.

Reference: Ebbe Almqvist (2003) History of Industrial Gases. Kluwer Academic/Plenum Publishers