Ford and Bradley — Footeite and Connellite. 673 



case with some of the specimens from the Bisbee occurrence. 

 It is found with cuprite which has a massive to granular struc- 

 ture with frequently small brilliant crystals projecting into the 

 cavities. On two specimens the connellite needles were observed 

 embedded in a pale bluish white material which was very soft 

 and had a felt-like appearance. It was very evidently an alter- 

 ation product of the connellite. This material was easily soluble 

 in hydrochloric and nitric acids and in ammonium hydroxide. 

 It was impossible to separate it completely from the associated 

 connellite and not enough w r as available for an analysis. It 

 gave distinct tests only for copper, chlorine and water, and in 

 general behaved like nantokite. Other specimens showed a 

 light blue compact material closely associated with the connel- 

 lite which gave the tests for chrysocolla. Atacamite was ob- 

 served, in one case being intimately associated with the con- 

 nellite. On another specimen, small cleavable masses of 

 spangolite were noted. The optical characters and chemical 

 reactions of the Tintic mineral were identical with those of the 

 material from Bisbee. 



Analyses. — Connellite from both of the new localities w T as 

 analyzed by Bradley. The methods used were as follows: 

 The mineral was dissolved in dilute nitric acid from which 

 solution the chlorine was precipitated and weighed as silver 

 chloride. The excess of silver in the filtrate was precipitated 

 by hydrochloric acid and removed. The nitric and hydro- 

 chloric acids were then removed by evaporation with sulphuric 

 acid and the copper was precipitated from the resulting solu- 

 tion as cupric sulphide and ignited in a current of hydrogen gas 

 and weighed as cuprous sulphide. The sulphuric acid was 

 precipitated from a hydrochloric acid solution by the addition 

 of barium chloride and weighed as usual. On attempting to 

 determine directly the amount of water present by heating in 

 closed tubes, it was found difficult to obtain neutral water 

 although the various methods ordinarily used to retain hydro- 

 chloric and sulphuric acids w T ere employed. In attempting to 

 explain this peculiarity, tests were made for the presence of 

 various other acids and surprisingly enough the mineral was 

 found to contain a small amount of nitric acid. Positive tests 

 for N 2 5 were obtained upon the connellite from both localities 

 in four different ways, namely by the ferrous sulphate, the 

 diphenylamine, the brucine and phenol disnl phonic acid 

 methods. Similar tests were made upon a portion of the small 

 crystal group obtained from the specimen of the original occur- 

 rence of the so-called footeite belonging to the American 

 Museum of Natural History with the result that it was also 

 shown to contain nitric acid. Because of the very restricted 

 amount of the mineral available for analysis it was possible to 



