J. E. Whitfield — The Rockwood Meteorite. 389 



gated separately, but from the fact of there being a number of 

 minerals mixed together, no satisfactory conclusions could be 

 drawn from the examination. The mass was therefore analyzed 

 as a whole with the following result : 



Si0 2 -- 41 



Al o 0, 9 



FeO 22 



CaO. 9 



MgO 8 



Fe 3 



Ni 1 



CI 



P 



S . 1 



92 



27 



94 



09 



76 



75 



74 



18=0-32 FeCl, 



65 



58 



99-88 



By the analysis of the portions soluble and insoluble in dilute 

 acid, it was found that the greater part of the lime and but a 

 trace of the magnesia had gone into solution, proving the 

 absence of olivine, and giving good grounds for the supposi- 

 tion that the rocky portion is mainly a mixture of anorthite 

 and a silicate related to augite, but very rich in iron. 



It will be noticed that the ratio between iron and nickel in 

 the metallic portion is greater than that in the rock. This is 

 accounted for by the fact that in the rocky part of the meteor- 

 ite, the iron, as metal, has been greatly oxidized, as is shown 

 by the large amount of rust covering the specimen, caused no 

 doubt by the chloride of iron present, and is reckoned as FeO, 

 accounting for the large proportion of iron in the supposed 

 augite. 



Owing to the bad condition of the fragments subjected to 

 analysis we have no grounds on which to compute the phos- 

 phorus and sulphur as schreibersite and troilite, but from the 

 fact of these minerals being among the more common constitu- 

 ents of this class of meteorites, and also that in the main analy- 

 sis of the rock portion phosphorus and sulphur were found, it 

 is probable that the phosphide and sulphide of iron are two of 

 the minerals present. 



One of the polished slices contained a nodule of about ■§■ 

 inch diameter, which was sacrificed in order that its nature 

 might be determined, and the following figures give the results 

 of analysis. The mineral was finely ground, the metallic 

 portion, if any, separated by aid of the magnet and- digested 

 in dilute hydrochloric acid. 



The insoluble portion was found to be 94 per cent, the com- 

 position of which is 



\ 



