Scientific Intelligence. — Mcteoroloyy, 185 



nected with the decomposition of the sulphates in sea-water increases 

 upon me every day, and I have now the pleasure to send you an abstract 

 of a paper, which you vnW. find at length in the 29th volume of the An- 

 nales de Chimie, p. 225, by Signer Guetano Giorgini, which oflfers the 

 strongest possible confirmation of my opinion. I trust that it may tend 

 to give confidence to the African expedition ; for if wo rightly know the 

 cause of tlie pestiferous exhalations upon the coast, the prevention of ill 

 effects is obvious and easy : — Steam through the salt-waters as fast as pos- 

 sible, and while obliged to be on them make a plentiful use of chlorine 

 fumigation, which instantly decomposes the sulphuretted hydrogen. — I 

 am, &c. 



J. F. Daniell. 

 Captain Washington, E.N. 



" The observation of Signer Giorgini has been draAvn to the state of the 

 atmosphere in the neighbourhood of certain marshes on the borders of the 

 Mediterranean ; and by reference to historical data, and various docu- 

 ments, he has proved the great importance which attaches to the circum- 

 stance of their being 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 modem authors have announced the fatal effects produced in 

 the neighbourhood of marshes by such mixture, and a local belief of the 

 same 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 Mediterranean, on the south by the 

 river Serchio, and on the north by the river Frigido, a torrent commenc- 

 ing 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 tor- 

 rents 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 dis- 

 charged 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 Mediterranean. 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 in- 

 fection over the neighbourhood of the most destructive kind. 



" In this way the effects of the malaria were reproduced annually in ih« 



