v /.. /' $ jolite, a rww copptr mineral. 377 



by standing uncovered in the air. Heated for an hour at 1«»«» C. 

 it lost about 0*49 j>t i r cent, but also regained Ehis by standing 

 in the air. The analyses were nil made on air-dry powder. 

 Water was determined by heating the mineral, weighed in a 

 platinum boat, in a hard glass tube containing a loose plug of 



irbonate at one end. through which the water vap 

 were conducted before absorption in I weighed chloride of caJ 

 ciuiu ruin A good ileal of chloride of copper distilled off 

 in the mineral In some cases the contents of the boat was 

 dissolved in nitric acid, the tube cleaned our carefully and a 

 analysis made on one portion. A new portion being 

 taken ir was dissolved in nitric acid and the chlorine precipi- 

 tated with Bilver nitrate. The weighed silver chloride when 

 tested was found to contain no bromine or iodine and when 

 ignited in hydrogen gas yielded a weight of metallic silver 

 eeing with the composition AgCl. After removing the excess 

 •he silver from the solution with hydrochloric acid the S< I 

 was precipitated with BaCl„ care being taken to avoid & loss 

 owing t<> the Bolubility of BaS0 4 in the aqua regia which was 

 present in the analysis. After separating the excess of barium 

 with sulphuric acid the solution was evaporated to expel the 

 nitric acid after which the copper was precipitated with hvdro- 

 Bulphide and weighed after ignition in hydrogen gas as 

 Cu S. A portion of the copper precipitate was carefully tested 

 for other metals, hut none were found. The filtrate from the 

 copper sulphide, when evaporated to dryness and ignited left 

 a residue which proved to be sulphate of alumina; this was dis- 

 ced in acid, precipitated in ammonia and weighed as Al,< > 

 A weighed quantity of the oxide was carefully tested for beryl- 

 lium, hut none was found, and after conversion into sulphate 

 and evaporation with the right quantity of K 2 S0 4 it yielded 

 alum crystals. The filtrate from the alumina yielded no per- 

 ceptible residue when evaporated to dryness proving that every- 

 thing had been separated from the solution. 



Pyrognostic and chemical tests. — Before the blowpipe the 

 mineral fuses at about 3 to a black slaggy mass, coloring the 

 flan en. On charcoal with soda in reducing flame it yields 



if metallic copper. Heated in the closed tube e;i 

 abundant water which has a strong acid reaction. In>oluble in 



■ 



r. but readily soluble in dilute acids. 

 The nt no known mineral similar to spangolite 



in composition; the very rare connellite from Cornwall, Eng- 

 land, whose chemical composition has never been determined, 

 be nearest approach to it, as it contain-, according to ( lonnel, 

 copper in combination with sulphuric and hydrochloric acid-. 

 but the crystalline form and physical properties of the two min- 

 erals are entirely distinct A- far a- can be found these two 



