in the Waters of the Ocean. 15 



subject, more and more convince me that the worst cases of 

 malaria are generally connected with the presence of sulphu- 

 retted hydrogen. 



There is a paper in the twenty-ninth volume of the Annates 

 de C/timie, p. 225, by Signor Gaetano Giorgini, which offers 

 the strongest possible confirmation of my opinion. 



" The observation of Signor Giorgini has been drawn to 

 the state of the atmosphere in the neighbourhood of certain 

 marshes on the borders of the Mediterranean ; and by refer- 

 ence to historical data, and various documents, he has proved 

 the great importance which attaches to the circumstance of 

 their beinc, at times, in communication with the sea, so as to 

 have a mixture formed between their waters and that of the 

 sea. Both ancient and modern authors have announced the 

 fatal effects produced in the neighbourhood of marshes by 

 such mixture, and a local belief of the same thing is very 

 common and strong. 



" On the south of the Ligurian Apennines is a marshy 

 shore, bounded on the west for twelve miles by the Mediter- 

 ranean, on the south by the river Serchio, and on the north 

 by the river Frigido, a torrent commencing at the foot of the 

 Apennines, in the state of Massa di Carrara, running three 

 or four miles over the land, and then falling into the sea. 

 The plain is from two to four miles wide, and is traversed by 

 a few short torrents or streams ; among these are the rivers 

 Camajore and Pietra Santa, which divide the plain into three 

 separate basins. The rain and spring waters which flow into 

 the three basins mentioned, are slowly discharged into the sea 

 by natural or artificial canals, penetrating the sand-bank, 

 which exist on the sea-side. 



" The level of these stagnant waters is between that of high 

 and low water in the neighbouring sea; there being but little 

 difference between these two points in this part of the Medi- 

 terranean. In this state of things, formerly, when the waters 

 of the sea arose from any circumstance (unless the waters of 

 the marshes were very high), they used to return up the 

 ditches, fill the basins, and inundate the country to the foot 

 of the mountains ; and with a north-west wind, the waves used 

 to penetrate with force to the interior. The mixture of fresh 

 and salt water thus formed, and which, in summer, was rarely 

 changed, became corrupt, and spread infection over the neigh- 

 bourhood of the most destructive kind. 



" In this way the effects of the malaria were reproduced 

 annually in the neighbouring country, with all their peculiar 

 horrors: the population, though small, presented feeble infants 



