THE 

 LONDON, EDINBURGH and DUBLIN 



PHILOSOPHICAL MAGAZINE 



AND 



JOURNAL OF SCIENCE. 



[THIRD SERIES.] 



JUL Y 1841. 



I. On the Spo7ilaneous Evolution of Sulphuretted Hydrogen 

 in the Waters of the Western Coast of Africa, and of other 

 Localities. By J. Frederic Daniell, For. Sec. U.S., 

 Prof. Chem. in King's Coll., London, fyc.* 



]VIY attention was first directed to the subject, which I 

 ■*■*-*■ shall have the honour of submitting to your notice this 

 evening, by the Lords of the Admiralty, in April 1840, who 

 sent me eight specimens, and afterwards two additional spe- 

 cimens, of water from the mouths of the rivers on the western 

 coast of Africa, with directions to analyze them, for the pur- 

 pose of discovering, if possible, the cause of the rapid decay 

 of the copper-sheathing of ships employed upon those stations. 



Of the comparative duration of the metal in the vessels of 

 the Royal Navy I have not been informed ; but the evil com- 

 plained of is well known also in the merchant service; and 

 upon inquiry of one of the largest copper-smelters in South 

 Wales, he assures me, that " the experience of between thirty 

 and forty years has led his mind to the conclusion that sheath- 

 ing copper will be as much or more injured on a nine months' 

 voyage to and along the coast of Africa, as by the wear of from 

 three to four years on any other trade." 



The first water which I examined was from the river at 

 Sierra Leone, taken at three miles from the mouth. Upon 

 drawing the cork of the bottle it was found to smell very 

 strongly of sulphuretted hydrogen. 



* Communicated by the Author; being the substance of a Lecture de- 

 livered to the Members of the Royal Institution on the 21st May, 1841. 

 Phil, Mag. S. 3. Vol. 19. No. 121. July 184-1. B 



