Mofetta is a name applied to a volcanic discharge consisting chiefly of carbon dioxide

Carbon dioxide

Carbon dioxide is a naturally occurring chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom...

, often associated with other vapours, representing the final phase of volcanic activity. The Oxford Dictionary of English

Oxford Dictionary of English

The Oxford Dictionary of English is a single-volume English language dictionary first published in 1998 by Oxford University Press. This dictionary is not based on the Oxford English Dictionary and should not be mistaken for a new or updated version of the OED...

 lists "mofetta" as an archaic term for the modern word fumarole

Fumarole

A fumarole is an opening in a planet's crust, often in the neighborhood of volcanoes, which emits steam and gases such as carbon dioxide, sulfur dioxide, hydrochloric acid, and hydrogen sulfide. The steam is created when superheated water turns to steam as its pressure drops when it emerges from...

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The word is used in the plural as mofette, or, following the French, mofettes. The volcanic vents yielding the emanations are themselves called mofette. They are not uncommon in Auvergne

Auvergne (région)

Auvergne is one of the 27 administrative regions of France. It comprises the 4 departments of Allier, Puy de Dome, Cantal and Haute Loire.The current administrative region of Auvergne is larger than the historical province of Auvergne, and includes provinces and areas that historically were not...

 and in the Eifel

Eifel

The Eifel is a low mountain range in western Germany and eastern Belgium. It occupies parts of southwestern North Rhine-Westphalia, northwestern Rhineland-Palatinate and the south of the German-speaking Community of Belgium....

, notably on the shore of the Laacher See

Laacher See

' or Laach Lake is a caldera lake and a potentially active volcano, in Rhineland-Palatinate, Germany, situated close to the cities of Koblenz , and Bonn , and closest to the towns Andernach , and Mayen . The caldera lake lies just 8 km from the river Rhine at Andernach...

; whilst other examples are furnished by the Grotta del Cane, near Pozzuoli

Pozzuoli

Pozzuoli is a city and comune of the province of Naples, in the Italian region of Campania. It is the main city of the Phlegrean peninsula.-History:Pozzuoli began as the Greek colony of Dicaearchia...

, the Valley of Death

Valley of Death

Valley of Death refers to any of the numerous landforms named Death Valley and to:*Valley of Death , the polluted city of Cubatao in Sao Paulo*Valley of Death , a 1939 Nazi mass murder and mass grave site in northern Poland...

 in Java, the Death Gulch in the Yellowstone Park and the series of mofette in the Székelyföld Hills, Transylvania

Transylvania

Transylvania is a historical region in the central part of Romania. Bounded on the east and south by the Carpathian mountain range, historical Transylvania extended in the west to the Apuseni Mountains; however, the term sometimes encompasses not only Transylvania proper, but also the historical...

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Depending of the mineral content of the different vapours, mofette may be used for therapeutic purposes as well. As carbon dioxide is heavier than the air, patients can use it as dry spa

Destination spa

A destination spa is a short term residential/lodging facility with the primary purpose of providing individual services for spa-goers to develop healthy habits. Historically many such spas were developed at the location of natural hot springs or sources of mineral waters...

, if certain safety regulations are complied with. The first known record about mofetta treatment for injuries is from the 16th Century, by Paracelsus

Paracelsus

Paracelsus was a German-Swiss Renaissance physician, botanist, alchemist, astrologer, and general occultist....

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Today, the balneo-technology of the dry carbon-dioxide gas-bath using frozen carbon-dioxide (dry ice) is also used to reproduce the effects of a natural mofette.