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MEMOIKS NATIONAL ACADEilY OF SCIENCES, VOL. XIII. 



can, of course, be noted from other meteorites with which it is classed, it being, for instance, more compact and of 

 finer grain than Beaver Creek and containing much less nickel-iron than Pipe Creek. 



Of its well-marked crystalline character, however, there can be no doubt, nor, to my mind, of its monogenic origin. 



Absorption by a siliceous magma, of iron in preference to nickel, seems to me to afford a reasonable explanation 

 of the high percentage of nickel in the metallic portion of the stone shown in the following analysis. Such a high per- 

 centage of nickel in the nickel-iron of stone as compared with iron meteorites is common and must be of some signifi- 

 cance. If the meteorite is simply tuffaceous in origin, one would expect the nickel-iron to have the composition of that 

 of the iron meteorites uninfluenced by the accompanying silicates, but such is not the case. 



Again, the outlines of the crystal individuals in the Long Island meteorite are sharply and fully developed and are 

 in stable and magmatic position with reference to each other. Some of them are larger than the individual chondri 

 and yet exhibit no sign of wear or fracture. Accordingly the believers in the tuffaceous character of all stone 

 meteorites would find, I think, little to support their views in an examination of this stone. I can see no indications 

 in its structure of any other origin than one of cooling in place from a fused magma. 



An analysis of the meteorite was made by Mr. H. W. Nichols, as follows: 



3.31 40.74 55.75 99.80 



The most striking feature of the composition revealed by this analysis is the high percentage of Cr 2 3 . I know of 

 no other meteorite which shows so high a percentage, more than 1 per cent being rare. Most of this was found in the 

 insoluble portion and may hence be referred to chromite, especially as examination of sections with the microscope 

 shows a large quantity of the red translucent grains which indicate that mineral. It may be worthy of remark, how- 

 ever, that the chromium mineral of the meteorite was more easily decomposed than ordinary chromite. Although 

 left as an insoluble residue after fusion with sodium carbonate, it went into solution on treatment with sulphuric acid 

 without requiring a separate fusion with acid sulphate of potash. The percentage of Cr 2 3 noted in the soluble por- 

 tion of the meteorite may probably be regarded as a constituent of the chrysolite, although its quantity here is above 

 the average. 



The quantity of A1 2 3 , shown in the soluble portion of the above analysis, is unusually high and is difficult to 

 account for, although it has not infrequently been reported by other analysts as a constituent of the soluble portion of 

 meteorites. 



Grouping the compounds of the above analysis which are known to enter into the composition of nickel-iron, 

 chrysolite, and bronzite, the following may be deduced as the probable composition of these three ingredients: 



COMPOSITION OF NICKEL-IRON. 



Fe 78. 65 



Ni 20. 26 



Co 1. 09 



100. 00 



