406 Dr. Walter Flight — History of Meteorites. 



' piddingtonite,' Gr. Eose considered it to be composed of olivine 

 and another mineral ' shepardite,' which has now been found to be 

 as hypothetical a species as ' piddingtonite.' Eammelsberg during a 

 recent examination of the meteorite determined it to consist of : 



Bronzite 86-15 



Olivine 10-92 



Ckroniite ... 2-39 



99-46 

 the separation with acid and sodium carbonate yielding the following 

 numbers : 



Si0 2 FeO MgO CaO Na,0 Chromite. 



A. Soluble ... 35-17 35-80 29-03 — — — 100-00 



B. Insoluble ... 55-55 16-53 2773 0-09 0-92 0-33 = 101-15 



Eammelsberg therefore finds this meteorite to have a much more 

 simple composition than the earlier investigations, and to consist 

 mainly of a bronzite and a few per cent, of olivine, in each of which 

 the Fe is to Mg as 1 : 3. 



According to the results given in Maskelyne's paper, the constitution 

 of this meteorite, or of the portion of it examined in the British 

 Museum Laboratory, appears to be yet more simple. A small amount 

 of the debris of the stone was found to possess the following com- 

 position : Oxygen. 



Silicic acid 45-370 24-197 



Iron protoxide 



Magnesia 



Lime ... 



Chromite 



99-997 

 A mottled grey-coloured mineral, forming the chief constituent of 



the meteorite, was twice submitted to analysis with the following 

 results : 



I. Oxygen. II. Oxygen. 



Silicic acid 52-831 28-176 52-725 28-120 



Iron protoxide... 21-863 4-859 22-992 5-109 



Magnesia 24-266 9-706 24-085 9-630 



Lime 0-502 0-143 — — 



Chromite 0-643 — — — 



19-060 ... 



4-236 



15-636 ... 



6-254 



2-214 ... 



0-632 



17-717 ... 



— 



100-105 99-802 



These numbers correspond with the formula (-§ Mg \ Fe) SiO s , 

 which is identical with the bronzite of the Manegaum meteorite 

 (which see). 



These results, it will be seen, do not indicate the presence of an 

 olivine. To check them, two weighed portions of the mineral were 

 subjected to the action of hydrochloric acid and sulphuric acid 

 respectively, with subsequent treatment with sodium carbonate in 

 each case, whereby the following constituents were removed : 



I. Oxygen. II. Oxygen. 



Silicic acid 1-507 0-804 3-900 2-080 



Iron protoxide... 0-974 0-216 1-799 0-399 



Magnesia 1-058 0-423 1-877 0-760 



3-639 7-576 



