56 MEMOIRS NATIONAL ACADEMY OF SCIENCES, VOL. XIII. 



The metallic part therefore comprises 17.13 per cent of the meteorite and is composed as follows: 



Fe 90.68 



Ni 8.80 



Co 49 



Cu 03 



100.00 



By the procedure outlined in one of the footnotes to the foregoing analysis the isolation of the magnetite from all 

 but a very small proportion of siliceous matter is easy. It then appears under the microscope as irregular grains of a 

 dull-black, lusterless surface. Only one grain presented an apparently octahedral aspect. 



The main portion of the meteorite material, now freed from all magnetic matter, was thoroughly mixed and pul- 

 verized. Its composition follows: 



Analysis of unmagnetic material. 



S 2 ' 21 \6.08 troilite. 



Fe" ' 3.87J 



Fe 24 ^ 75chromite. 



Cr 2 3 51 



Si0 2 45. 87 



Ti0 2 09 



A1 2 O 3 2. 30 



FeO 12.44 



NiO 07 



MnO 26 (too low). 



CaO 1. 96 



MgO 28. 24 



K 2 15 



Na-jO 98 



Li 2 O None. 



H 2 above 100 C 34 



PA 30 



Cl... - Trace. 



99.83 



The assumption of FeO as the sole divalent element in the chromite is entirely arbitrary. Qualitative tests on a 

 minute quantity separated from the silicates showed that the mineral carried magnesia and alumina also. The extremely 

 weak magnetism of the troilite appears clearly from the fact that the electromagnet produced only a barely perceptible 

 concentration of it in the magnetic mixture, as shown by comparing the percentages of troilite and of silicates therein 

 with those just above. 



A portion of the unmagnetic powder was then divided into a soluble and an insoluble part by digesting for a few 

 hours with dilute hydrochloric acid on the water bath, filtering, separating gelatinized silica by dilute solution of 

 potassium hydroxide, and repeating the treatment of the residue with acid and alkali. In this way there was decom- 

 posed 51.11 per cent of the whole. The composition of both soluble and insoluble parts as actually found by analysis 

 is as follows, the S and P 2 O 5 being taken from the previous analysis, as also the water of the soluble part after allowing 



for the trifle belonging to the insoluble portion. 



Soluble portion. Insoluble portion. 



S;:::::::::::::::::::::::;:::;:::::::::::::::: J 



"1 .04 chromite. ' 0.73 chromite. 



| 



UTjl/j .......................................... Oo 



Si0 2 ......................................... 17.03 . 27.74 



Ti0 2 ................................................ .09 



A1 2 3 ......................................... 25 2.34 



FeO .......................................... 8.69 3.85 



NiO .......................................... 04 Trace. 



MnO .......................................... 12 .17 



CaO ............................................ 46 1.65 



MgO ......................................... 17. 24 11. 14 



K,0 ........................................... 01 .12 



Na 2 O ........................................... 06. .90 



H 2 O above 100 C .............................. 31 .03 



P 2 6 .......................................... 30 .................. 



Cl ............................................ Trace ................... 



Loss ........................................... 48 .13 



51. 11 48. 89 



