472 G. P. Merrill — Composition of Stony Meteorites. 



were sometimes given as simply ferrous sulphide and some- 

 times as sulphur. Where such calculations were necessary, 

 the percentage of iron was added to the amount given in the 

 analyses as existing in the metallic state.* 



The following list shows the highest and lowest percentages 

 of any given constituent in the analyses here averaged. 



Highest Lowest 



Si0 2 61*15 26-05 



A1 2 3 '_-__ 11*05 0-00 



Fe 27-00 0-00 



FeO 30-44 0-99 



CaO 7-03 0-00 



MgO 39-04 6-44 



Na 2 0._ 3-94 0-00 



K 2 4-31 f 0-00 



Cr a 3 + Fe a O,... 6*33 0-00 



NiCo 4-21 O'OO 



S 7-47 0-00 



fit would seem that this must be an error, since the stone (that of 

 Zsadany, Hungary) is described as consisting essentially of olivine and 

 pyroxene, and no reference made to feldspars. 



For comparison of these results with terrestrial rocks, the 

 following are given : 



Average composition of terrestrial igneous rocks as calculated by (III) 

 Clarke and (IV) Washington.! 



Ill IV 



Si0 9 .. _.- 60-91 58-239 



A1 2 0,.__. 15-28 15-796 



Fe 2 3 2 63 3-334 



FeO 3-46 3-874 



MgO 4-13 3-843 



CaO 488 5-221 



Na 3 3-45 3-912 



K 2 2-98 3-161 



H 2 at 100°. _ 0-41 0-363 



" above 100° 1'49 1-428 



Ti0 2 0-73 1-039 



P O ._ 0-26 0-373 



100-61 100-583 



fBull. 330, U. S. Geol. Survey, 1908. 



*The writer regards these results as only approximations, and suggestive. 

 The recalculation of many of the analyses'is attended with so many uncertain- 

 ties, that it is even probable that slightly different results would be obtained 

 in going over the same ground a second time. So far as the main constitu- 

 ents — the silica, alumina, lime, magnesia, potash and soda — are concerned, 

 he believes the averages as good as can be obtained with available material. 



