862 PROCEEDINGS OF THE ACADEMY OF [DeC, 



In fact we can now prove that this crater is due to the collision with 

 the earth of an extra-terrestrial body, possibly a small asteroid, which 

 was presumably metallic in nature. 



We do not know, and indeed may never know, whether this great 

 meteor was originally an irregularly shaped fragment or whether it 

 was a spheroid, but we have strong reason to believe that the composi- 

 tion of the exterior was that of nickeliferous iron, containing in minute 

 quantity platinum and iridium. 



Since acquiring possession of the property, we have learned that this 

 meteoric fall has been the subject of many papers and that the com- 

 position of the iron, and the fact that it contains microscopic diamonds, 

 has been well known, upwards of ten tons of iron specimens having 

 been shipped away from this locality; although, singularly enough, 

 the presence of platinum and iridium has not been suspected. The 

 presence of these metals was ascertained for us by ^Ir. H. H. Alexander, 

 of the Globe Smelter, Denver, l^y subjecting the iron and the magnetite 

 (the origin of which we shall attempt to explain hereafter) to the fire 

 assay test, samples of each having been sent to him for the purpose. 

 Their presence has been also confirmed by the very high chemical 

 authority, Dr. J. W. Mallet, F.R.S., of the University of Virginia, whose 

 letter on the subject is herewith submitted.^ 



'University op Virginia, 

 Charlottesville, Va. 



August 17, 1905. 

 D. M. Barringer, Esq., Philadelphia. 

 Dear Mr Barringer: 



About a fortnight ago I was at last able to undertake the examination you 

 desired of the residue sent me by Mr. Alexander from solution in dilute hj'dro- 

 chloric acid of 2.5 lbs. of the Canon Diablo meteoric iron, and I now report results: 



I first repeated twice the assay experiments made by Mr. Alexander, and 

 obtained substantially the same results that he did. 



It then seemed to me desirable to apply a method which should not involve any 

 addition of foreign metals (though I have full confidence in the purity of Mr. Alex- 

 ander's lead, gold and silver), and to avoid determination of platinum "by loss." 



I therefore boiled the greater part of the residue sent me by him with a mix- 

 ture of strong hydrochloric and nitric acids as long as there was any action. 

 This was a very tedious affair, the Schreibersite (phosphide of iron and nickel), 

 which formed a large proportion of the residue, being but slowly attacked, and 

 there being a strong tendency to boiling over from sudden, irregular evolution of 

 nitrogen dioxide. The solution obtained was evaporated two or three times 

 with hydrochloric acid, diluted, filtered and treated with a current of sulphuretted 

 hydrogen, first cold and then while heated. This gave a copious precipitate of 

 sulphur (from reduction of ferric to ferrous chloride) colored brownish by the sul- 

 phides of the platinum metals. 



This precipitate was filtered off, well washed with water, dried and burned. 

 The small residue left was then reconverted into clilorides, and the platinum and 

 iridium separated in the usual way, by partial reduction of the iridium salt and 

 precipitation of that of platinum with ammonium chloride. 



