in the Waters of the Ocean. 7 



It is difficult to conceive how such a striking and important 

 fact as the impregnation of the waters of the Ocean, upon such 

 a long line of coast, with this deleterious gas, should so long 

 have escaped observation. 



Upon searching for evidence of a similar phenomenon 

 having been observed before, I have found in the Phil. Trans. 

 for 1819, a memoir by the late Dr. Marcet, " On the Specific 

 Gravity and Temperature of Sea Waters in different parts of 

 the Ocean, and in particular Seas, with some account of their 

 saline contents." Out of sixteen specimens which he exa- 

 mined he found one which was brought by Capt. Basil Hall 

 from the Yellow Sea in the Chinese Ocean, which, from the 

 account which he has given, must probably have been as 

 highly charged with sulphuretted hydrogen as those from the 

 coast of Africa ; and he observes, " there is something in the 

 development of sulphur in sea water which is by no means 

 well understood." 



He also noticed that a specimen obtained by Mr. Schmidt- 

 meyer, going to South America, from lat. 10° 50' N., long. 

 24° 26' W., had an hepatic smell, and had blackened the bot- 

 tle in which it was contained. 



Since the report, which I had the honour to make to the 

 Admiralty, Sir William Burnett has been kind enough to 

 furnish me with the analysis, by Mr. Garden, of some bottles 

 of water, collected by Dr. Mc William, of Her Majesty's ship 

 Scout, in March 1839, in the river Bonny, of which the fol- 

 lowing are the particulars : — 



1. Water from the river Bonny, taken half a mile inside 

 the mouth, on the 12th of March, 1839, just before the com- 

 mencement of the rainy season. 



Each imperial pint of this water contained 245 grains of 

 saline matter, consisting of the following ingredients: — 

 Sulphate of Magnesia 

 Do. of Lime 

 Muriate of Magnesia 

 Do. of Soda 

 Sulphuretted hydrogen, *680 cub. in. (5*44 cub. in. per gall.) 



2. Water from the mouth of the river Lagos, lat. 6° 20' N., 

 long. 3° 30' E. nearly. 



Each pint yielded 240 grains of saline matter, consisting of 

 the same ingredients as those above mentioned ; also 

 Sulphuretted hydrogen, 1*844 cub. in. (14*752 cub. in. per gall.) 



3. Water from the river Bonny, taken off Ju-ju Point, on the 

 12th of March, 1839, about one mile and a half within the mouth. 



One pint yielded 200 grains of saline substances, as above, and 

 Sulphuretted hydrogen, '505 cub. in. (4*04 cub. in. per gall.) 



