MANGANESE. 



fewer than 5 proportions, and form 5 oxides, the 

 composition of which is as follows : 



manganese. 



Oxides of 



1 Protoxide . 3-5+1 



2 Deutoxide . . . 3-5 + 1-5 



3 Tritoxide . . . 3-5 + 2 



4 Manganous acid . . 3-5 + 3 



5 Manganesic acid . . 3-5 +4 



9. Berzelius describes an oxide of manganese 

 containing less oxygen than any of the preced- 

 ing. It was obtained by leaving metallic man- 

 ganese for more than a year in a phial not very 

 closely corked. It fell into a dark coloured 

 powder, which, according to Berzelius' analysis, 

 or rather calculation, was a compound of 



Manganese . . 100 

 Oxygen . . 10-666 



I have had no opportunity of making any ex- 

 periments on this supposed oxide : but, if it 

 exist, it must be a compound of 3 atoms man- 

 ganese with 1 atom oxygen. This would con- 

 sist of 



Manganese 10-5 or 100 

 Oxygen 1-0 - 9'5238 



which differs but little from the estimate of Ber- 

 zelius. 



10. Dr. John found, that when metallic man- 

 ganese is put into water, that liquid was slowly m 



