466 Prof. Church on Tasmanite, 



in a Phillips's precipitating-glass, and strong hydrochloric acid 

 poured upon it. A trace of carbonic anhydride was thus set 

 free from the small quantity of carbonate of calcium present, 





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while the alumina and ferric oxide of the mineral were partly 

 dissolved. These chemical actions served to break up the mine- 

 ral, and the organic ' scales ' became for the most part disen- 

 gaged, and floated, owing to the high gravity of the hydrochloric 

 solution, which had been further increased by the addition of 

 chloride of calcium. The scales were collected from the surface 

 by a strainer, and washed repeatedly by decantation; by this 

 method of purification the inorganic matter in them was 

 reduced to a minimum. 



The substance thus prepared presents such remarkably dis- 

 tinct chemical and physical characters, that I venture to assign 

 to it a distinct name, Tasmanite. 



I have already described the mode of occurrence and the phy- 

 sical appearance of the Tasmanite scales ; the action of certain 

 chemical reagents and of heat upon this substance may now be 

 recorded : I should mention that the density of the substance is 

 about 1*18 ; its hardness 2. It is translucent, of a reddish-brown 

 colour. Lustre resinous, and fracture conchoidal. 



Hydrochloric acid has no action on Tasmanite ; nitric acid 

 slowly oxidizes it, disengaging carbonic acid and pernitric oxide, 

 while the sulphur appears as sulphuric acid. If the action of 

 the nitric acid be stopped before all the substance has disap- 

 peared, the residue will be an orange-brown powder, which 

 burns still more readily than Tasmanite, but it is not explosive. 



