26 FETID MATTER IN SEA- WATER. 



Besides the saliiie contents of the sea, a variable 

 amount of fetid matter, probably derived from decay- 

 ing animal and vegetable remains, has been found in 

 most latitudes : and if sea-water be set aside in a vessel, 

 it will frequently even become putrid from the presence 

 of such matter. The late Professor Daniell,* in a lec- 

 ture delivered at the Royal Institution, gives details of 

 many experiments made by him on water brought from 

 the west coast of Africa, from which it appears that 

 the tropical sea, extending over many degrees of lati- 

 tude, evolves enormous quantities of sulphuretted hy- 

 drogen, a gas highly prejudicial to health, and very 

 destructive to the copper fastenings and sheetings of 

 ships. The space affected along the West African 

 coast has been found to extend for sixteen degrees of 

 latitude, and to a distance from land of at least 40 miles; 

 thus some 40,000 square miles are contaminated. Mr. 

 Daniell's inquiries were instituted at the request of the 

 lords of the Admiralty, who, as well as merchants 

 trading to the Gold Coast, had found that the copper 

 on their ships perished much more rapidly on the Afri- 

 can coast than elsewhere ; and Mr. Daniell mentions 

 one case in which a court of law compelled a contractor 

 to pay heavy damages to a merchant to whom he had 

 supplied sheet-copper for a ship employed on an Afri- 

 can voyage, because it was supposed that the copper 

 must have been unsound, as it perished after a very 

 short time ; and chemists, who were examined as evi- 

 dence on the trial, had declared that there was nothing 

 in sea- water which would corrode the copper so quickly. 

 * See Lend. Edin. and Dublin Magazine for July, 1841. 



