274 W. E. Hidden — Edisonite^ a new mineral. 



only 0*0770 grams were used for the chemical analysis. In 

 order to determine how mnch reliance could be placed on an 

 analysis made upon so small a quantity an equal weight of 

 rutile was analyzed by exactly the same method, and it may be 

 said here that the behavior of the two was exactly similar 

 throughout. T^e method of analysis was as follows : The 

 finely powdered mineral was decomposed by fusion with acid 

 sulphate of potash. The solutions in water which were turbid, 

 were treated with strong hydrochloric and a little sulphuric 

 acid, evaporated to dryness and heated till all the hydrochloric 

 acid was driven off ; when treated again with water the solu- 

 tions were perfectly clear ; they were diluted to a volume of 

 500 c. c, a solution of S0 2 in water added to reduce any iron, 

 and then boiled for an hour and a half, replacing the water as 

 it evaporated. The precipitated Ti0 2 was allowed to settle and 

 was then filtered and washed. The oxide ignited over a blast 

 lamp, lost nothing by further ignition with ammonium car- 

 bonate. The filtrate was evaporated to small bulk, the iron 

 oxidized with nitric acid and ammonia added in excess ; this 

 caused a slight precipitate, which in the rutile was light colored 

 and after weighing gave with the borax and salt of phosphorus 

 beads chromium reactions ; in the edisonite it was red and gave 

 iron and probably titanium reactions. The results are as follows : 



Rutile. Edisonite. 



Ti0 2 precipitated by boiling *0756 -0744 



Trace of oxide from the filtrate -0022 -0033 



Loss on ignition -0002 '0001 



•0780 -0778 



Weight of mineral taken *0780 '0770 



These results show that the edisonite is a nearly pure Ti0 2 

 like rutile. The only other constituent that could be detected 

 was a trace of iron." 



Careful search at the above locality, since the finding of the 

 above described specimen, has failed to bring to light more 

 than one additional example, and that a minute one found last 

 summer ; the writer thinks however, he has lately identified this 

 mineral on the Pilot Mt. in Burke Co., X. C, with the same 

 associations. 



Since the composition of this mineral is thus proved to be 

 pure titanic oxide, and since the crystallization seems to distin- 

 guish it from the three forms of Ti0 2 already known, the min- 

 eral must be regarded as a new one and sufficiently character- 

 ized to merit a name. I therefore propose for it the name 

 Edisonite, after Mr. Thomas Alva Edison, through whose 

 generosity the journey was made on which this mineral was 

 found, and also because of his always ready interest and help 

 toward scientific research. 



