May, 1902. Meteorite Studies, I — Farrington. 291 



it has followed cracks and fissures, is usually scarcely a millimeter, the 

 color changing beyond this through reddish to black before the dark 

 green of the unstained stone is seen. 



Over a large part of the surface of the stone as found appeared a 

 white amorphous coating which adhered very firmly. It could be 

 removed by treatment with weak acid and most of it has been taken 

 off in this way since the arrival of the stone at the Museum. When 

 its substance is examined chemically it is found to be carbonate of 

 lime containing a small percentage of clay. There can be little doubt 

 that this coating is derived from the calcareous soil in which the stone 

 lay for an unknown period, the carbonate of lime from the soil doubt- 

 less spreading over the meteorite surfaces through capillary attraction 

 and cementing upon the stone some of the surrounding clay. In 

 some cavities of the stone a much greater proportion of soil is held, 

 and at many points the cementing agent is iron oxide, derived doubt- 

 less from the oxidation of the metallic grains of the meteorite. 



The unaltered stone when exposed by fresh fracture is of a dark 

 green color, varying to black, although the latter shade may be due to 

 staining from terrestrial oxidation. The stone is fine-grained, tough 

 and compact. Occasional portions exhibit a slight porosity, giving a 

 slag-like appearance. Such areas are however small and the pores of 

 small size. The proportion of metallic ingredients is not large but 

 they are quite uniformly distributed. 



The metallic grains show most plainly on a polished surface, the 

 distribution and quantity being illustrated in Fig. 3. Occasionally 

 well-marked aggregations of these may be seen. None of the 

 surfaces that I have examined show arrangement of the grains in lines 

 or systems of lines such as have been noted in a number of stone 

 meteorites by Reichenbach* and Newtonf. The largest metallic 

 grain I have seen in the Long Island meteorite has a diameter of 1.5 

 mm. From this size all gradations may be found down to the minut- 

 est grains, examination with a lens bringing out many not visible 

 to the naked eye. 



The bronze-yellow color and comparative softness of many of the 

 grains as exhibited on a polished surface mark them as troilite, in con- 

 trast to the silver-white color and greater hardness of those composed 

 of nickel-iron. Further identification of the grains can be obtained by 

 isolating them or by treating a polished surface of the meteorite with 

 copper sulphate. On the polished surfaces examined the number of 

 troilite grains is evidently much in excess of those of nickel-iron. 



♦Ueber das Gefflge der Steinmeteoriten. Pogjjendorff' s Annalen 1859, vol. 108, pp. 291-311. 

 + .\mer. Jour, of Science, 1893, 3rd ser., vol. 45, pp. 152-3. 



