Maremme (sing, marcmma, a salt marsh), tracts of marshy country in some parts of middle Italy, on the Mediterranean coasts, especially from the mouth of the Cecina to Orbetello, which are extremely unhealthy from midsummer to the middle of autumn. During this period it is dangerous to spend even a single night in the Maremma; those who do so are almost surely attacked by fever. There is nothing apparent in the air, either to sight or smell, to account for this insalubrity; on the contrary, the atmosphere seems to be remarkably clear and pnre. The malaria does not proceed from the water of the marshes, for it is equally virulent on dry elevations, and has been attributed to unhealthy exhalations of sulphur and alum in the soil. In ancient times the Cam-pagna di Roma, which is now almost deserted in consequence of the malaria, was cultivated like a garden, and was the seat of a dense population. The city of Rome itself has been invaded by the mephitic air, and the malarious fever prevails in some of the streets. The Maremme, in different basins, occupy altogether an area of nearly 1,000 sq. m.
Of late years efforts, which to some extent have been successful, have been made to redeem the marshes by drainage, banking in the lakes, planting trees, and bringing the ground into tillage.