198 DESCRIPTION AND ANALYSIS 



It displays no electric signs, either naturally or by 

 heat or friction. 



It is not magnetic, either in the common way, or 

 by the ingenious method of double magnetism which 

 we owe to Abbe Hauy. 



The acids do not act upon it when cold. When 

 digested a long time with boiling nitro-muriatic acid 

 about 10-100 is dissolved. The residue is of a 

 lighter colour. 



Its chemical composition was ascertained by two 

 analyses, the results of which were strikingly simi- 

 lar, and were as follows :* 



* The mode of analysis was as follows. Having by prelimi- 

 nary experiments ascertained that this mineral was chiefly com- 

 posed of silex, lime, oxide of manganese, and oxide of iron, 

 and suspecting the presence of alumine, magnesia and oxide of 

 zinc from its gangues the Franklinite, Garnets, &c. I treated 

 it as follows : the finely pulverized mineral was fused in a silvei 

 crucible, with three parts of caustic potash and kept in fusion 

 during half an hour; the fusion was readily obtained, the mineral 

 communicated to the mass a reddish colour, with a greenish 

 tinge on the edges. Having diluted the mass with water, and 

 saturated with muriatic acid, a complete solution ensued. By a 

 careful evaporation to dryness, the silex became insoluble in 

 water slightly acidulated, while all the other ingredients were dis- 

 solved. By the addition of a solution of saturated hydro-sulfate 

 of potash, the lime and magnesia (if any,) were separated from 

 the other substances which were precipitated. (Care had been 

 taken to ascertain that the hydro-sulfate used, precipitated nei- 

 ther of these earths.) Oxalate of potash was then added to pre- 

 cipitate the lime, after which, no precipitate resulting from the 

 addition of sub-carbonate of soda, it was evident that this solution 

 contained neither magnesia nor any other substance, except the 



