[ 18 ] [Jak. 



MIASMA OF THE MARSHES CONTIGUOUS TO THE MEDITEURANEAN.* 



A MARSHY Strand extends along the Mediterranean, between the 

 rivers Serchio and Frigido, in the territory of Massa de Carrara, and 

 appears to be formed by the sands deposited by the Serchio and the 

 Arno in the gulf which formerly reached to the foot of the Ligurean 

 Appenines ; for the bottom of the marshes is formed of the same sand 

 as that of the coast, which increases yearly in breadth, by an alluvion of 

 four or five fathoms. This district comprizes three lakes, viz. Massa- 

 ciuccoli, Delia Torre et di Motrone, and de Petrotto, each of which has 

 a natural or artificial communication with the sea, into which they dis- 

 charge their superfluous waters. But as their level is lower than that of 

 the sea at high water, they were overflowed by the spring tides, or 

 whenever the libecciata (north-west wind) blew strongly. The mixture 

 of salt and fresh water in the lakes, slowly and seldom renewed during 

 summer, became corrupted, and infected the air. Tlie effects of the 

 cattiva aria are at present too well known to render it necessary to go 

 into any detail upon the miserable state to which the inhabitants in the 

 neighbourhood of these lakes were reduced. Suffice it to say, that they 

 were continually subject to diseases of the liver and spleen ; and that 

 the population was composed of languishing children, and sickly men 

 and women, though in the prime of life. Old age was unknown amongst 

 them. Such was the state of things before the year 1741, when a par- 

 tial attempt was made to purify the air. One of the principal causes of 

 the insalubrity of the air in similar situations as that described above 

 was known to the ancients, for Vitruvius, in his " Architecture," book 

 1st, chap, iv., says that no town should be built near a marsh, the level 

 of which was not above that of the sea. For in the case where 

 it was not so, the salt-water, driven by the tide or high winds, 

 had no means of flowing off afterwards. Silvius, Donat, P*ringle, 

 Boerhave, Monsignor Lancisi, and others, have more or less clearly 

 intimated that it is principally from those marshes in which there is a 

 mixture of fresh and sea-water, and in which this mixture remains for a 

 long time exposed to the summer sun, that arise the most deleterious 

 miasmata. Tliis opinion had, however, hitherto been supported by no 

 direct proof; for to ascertain with certainty that the insalubrity of the 

 air in the neighbourhood of marshes where a mixture of fresh and salt 

 water existed was caused by this mixture, it was necessary to permit 

 and hinder, successively, the communication between the fresh and sea 

 water, and thereby become assured that their separatioti was followed 

 by a purification of the air, and that their re-meeting was as certainly 

 accompanied by mephitic and pestilential exhalations. This experiment 

 has been tried in our days, with the most complete and almost unhoped- 

 for success. The following are the details : — In 1714, Gemignano 

 Rondelli, the engineer of Bologna, offei-ed to attempt separating the 

 water of the sea fn.m those of the lakes. In 1730, the celebrated 

 Eustache Manfredi made a similar proposal. In 1736, Bernardino 



^ Substance of a Memoir upon the causes of the insalubrity of the air in the 

 neighbourhood of marshes in communication with the sea. Read at the Eoyal 

 Academy of Sciences, at Paris, by Mr. Gaetano Giorgini, Member of the Academy of 

 Lucca. 



