164 Scientific Proceedings, Royal Dublin Society. 



No. 2. 



Since writing this paper I found a deposit of manganese accumulating 

 in a mine that had been abandoned for about five years ; the water 

 which formed this deposit came through a crack in the roof, from a bog 

 about 200 feet above. The deposit was chiefly found on the sides and 

 floor of the level as a black oozey mass of which the following is an 

 analysis : — 



Manganic Sesqui-Oxide, . . 56*4 



Ferric Oxide, .... 15-8 



Lime, ..... 6'0 



Magnesia . . . . 1"2 



Water, . ... 19-7 



99-1 



