OF ARKANSAS. 1£5 



Composition: 



Silica 1 .449 



Oxide of zinc 62.SG4 



Oxide of iron trace 



Lime 1 .'322 



Magnesia trace 



Carbonic acid, (loss on ignition) 34.095 



99.730 



The rational composition is, perhaps: 



Silicate of zinc 2.748 



Carbonate of zinc 94.925 



" « lime •' 2.360 



100.033 

 which requires 34.398 per cent, of carbonic acid, instead of 34.095, as 

 found. 



No. 57. Nitre earth; labeled "average nitre-earth, from J. T. Thomp- 

 son's nitre-cave on Cave creek, Newton county." 



Time did not, at present, permit more than a qualitative examination 

 of the watery extract of this earth. It was found to contain: 



A large amount of sulphate of lime; 

 Nitric acid; 

 Magnesia; 

 Potassa; 



Chlorine, and a very small quantity of 

 Phosphoric acid. 

 As soon as circumstances allow, I shall report a complete analysis of 

 this earth. 



