60 



Made of Lancaster. 



tinge when exposed to the oxidating flame. With cai- 

 bonate of soda it swells and decomposes^ but does not 

 melt. Moistened with nitrate of cobalt and exposed to 

 the blowpipe it acquires a fine blue color. It dissolves 

 slowly in phospliate of soda. 



ANALYSIS. 



The mineral was broken into fragments in a steel 

 mortar, and reduced to impalpable powder in one of 

 agate. The powder was of a greyish white color. 



Process A, To determine the quantity of water it 

 contained, fifty grains of the powdered mineral were sub- 

 jected to a red heat for fifteen minutes in a platina cap- 

 sule. It became of a brownish color, and when weighed 

 was found to have lost 0,75 gr. The change of color was 

 owing to the conversion ofprot into per oxide of iron. 



Process B. To separate the oxide of iron the powder 

 was digested with muriatic acid for six hours, and when 

 thrown on a filter, washed, dried, and ignited, was found 

 to have lost three grains. The filtered liquid was now 

 treated to excess with liquid ammonia, and the precipitated 

 oxide of iron collected on the filter, washed, dried and 

 ignited with a little wax to reduce it to the state of prot- 

 oxide. It was entirely taken up by the magnet, and 

 when weighed amounted to 2 grs. 



Process C. The^ powder firom which the iron had 

 been separated was now attacked by three times its 

 weight of pure caustic soda, to which sufficient water was 

 added to forai a thin paste with the powdered mineral. 

 The whole in a platina crucible was first heated carefully, 

 to expel cautiously the excess of w^ater, the cover being 

 nearly close over the crucible. It was then covered and 

 subjected to a full red heat in the fiimace for an hour. 



i 



