THE NOCOLECHE METEORITE— COOKSEY. 53 



sulphuretted hydrogen. The remaining portion of iron was then 

 thrown down by making the solution alkaline with ammonia. 



II. 3.0086 grams were separately dissolved in a mixture of 

 nitric and hydrochloric acids to estimate the sulphur and phos- 

 phorus. 



III. 2-5045 grams were dissolved in hydrochloric acid, the 

 residue and copper separated, the filtrate made up to 500 cc, and 

 50 cc, of this taken to estimate the iron, nickel, and cobalt. The 

 iron was separated from the nickel by precipitation with ammonia. 



IV. A small piece of very bright iron, shewing brilliant cleavage 

 surfaces, and weighing '.STSS gram, was analysed for iron. It 

 was obtained from the vicinity of a troilite nodule. 



IV. 



97 05 



The iron is active towards acids and sulphate of copper. 



Troilite. 

 The material for analysis was obtained from a nodule, the 

 specific gravities of two pieces of which, weighing '3746 gram, 

 and 1-3704 grams, were found to be respectively 5*50 and 5-442. 

 On powdering and treating with a concentrated solution of sul- 

 phate of copper, a copious precipitate of metallic copper was 

 very quickly formed. To remove all the iron the powder was 

 boiled with a concentrated solution of sulphate of copper for a 

 quarter of an hour.* A black product was finally obtained after 

 washing, which had a specific gravity of 4'66, and was found to 

 be sulphide of copper containing only 6-94 per cent, of iron. An 

 attempt was then made to separate the troilite from impurities 

 by repeatedly washing and separating the lighter and heavier 

 portions. A pi'oduct was in this manner obtained which curiously 

 had a specific gravity of 4^788, but on analysis was found to con- 

 tain 20*32 per cent, of sulphur and 73^49 per cent, of iron. The 

 iron must therefore be intimately mixed with the troilite. It was 

 finally ascertained that the iron could be removed by standing 

 for some hours with a solution of either sulphate of copper or 



* Stanislas Meunier, Encyclopedie chimique, ii., 1884, App. 2, Meteor- 

 ites, p. 57 ; W.Crookes, Select Methods in Chemical Analysis, 1886, p. 201. 



