1823.] Change of Musket Balls in Shrapnell Shells. 141 



I was able by referring to the statement to convince him and 

 his friend that if my papers had done him wrong, / at least 

 had endeavoured also to do him right*. 



Believing that I have now said enough to preserve my own 

 "honest fame" from any injury it might have risked from the 

 mistakes of Dr. Davy, I willingly bring this letter to a close, 

 and trust that I shall never again have to address you on the 

 subject. 



I am, my dear Sir, yours, &c., 



M. FARADAY. 

 Richard Phillips, Esq., $c. $c. 



Change of Musket Balls in Shrapnell Shells -\. 



MR. MARSH of Woolwich gave me some musket balls which 

 had been taken out of Shrapnell shells. The shells had lain in 

 the bottom of ships, and probably had sea-water amongst them. 

 When the bullets are put in, the aperture is merely closed by a 

 common cork. These bullets were variously acted upon : some 

 were affected only superficially, others more deeply, and some 

 were entirely changed. The substance produced is hard and 

 brittle, it splits on the ball, and presents an appearance like some 

 hard varieties of earthy haematite ; its colour is brown, becoming, 

 when heated, red ; it fuses on platinum foil into a yellow flaky 

 substance like litharge. Powdered and boiled in water, no 

 muriatic acid or lead was found in solution. It dissolved in 

 nitric acid without leaving any residuum, and the solution gave 

 very faint indications only of muriatic acid. It is a protoxide of 

 lead, perhaps formed in some way by the galvanic action of the 

 iron shell and the leaden ball, assisted, probably, by the sea- 

 water. It would be very interesting to know the state of the 

 shells in which a change like this has taken place to any extent ; 

 it might have been expected, that as long as any iron remained, 

 the lead would have been preserved in the metallic state. 



* Phil. Mag. 1834, iv. p. 261. 



t Quarterly Journal of Science, xvi. 163. 



