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Analysis of the Green Earth from Rancocas Creeks New 

 Jersey. By Henry Seybert. Read May 22d, 1822. 



This mineral, of a dark green colour, occurs earthy 

 and granular ; it is opake, and without lustre ; when 

 breathed upon, it emits an argilaceous odour ; specific 

 gravity 2.777 ; before the blow-pipe it fuses and yields a 

 black vitreous globule. 



PRELIMINARY ESSAYS. 



A portion of the mineral, finely pulverised, was boiled 

 in water ; the filtered liquor, tested with nitrate of barytes, 

 nitrate of silver, and oxalate of ammonia, gave only slight 

 traces of sulphuric and muriatic acids and lime. The li- 

 quor, on examination, proved to be free from iron. Muri- 

 atic acid occasions no effervesence with this substance. 



ANALYSIS. 



A. 3 Grammes^ of the pure mineral, in the state of a 

 fine powder, were exposed to a red heat, in a platina cru- 

 cible ; the colour became reddish brown ; to effect the 

 entire peroxidation of the iron, it was treated with nitric 

 acid, and again calcined at a strong red heat ; it then 

 weighed 2.78 grammes, the diminution of weight was 

 0.22 grammes, but by calculation, it will appear that the 

 protoxide of iron contained in the mineral, must have ab- 

 sorbed 0.074 grammes in passing to the state of peroxide; 

 therefore, the water expelled by calcination amounts to 



* A gramme is equal to 15.4457 English grs. Troj weight 



