METEORITES OF NORTH AMERICA. 103 



slight residue before a qualitative test could be made. Curiously enough it did not appear in Nos. 1 and 4, possibly 

 from the accidental presence of enough chlorine in the nitric acid to dissolve the small amount of stannic oxide as fast 

 as it formed. If this was not the case, it must be presumed that the tin does not belong to the schreibersite but to 

 another mineral that is not generally distributed throughout the meteoric mass, so that it only appears in certain por- 

 tions of the residue. 



As in the course of this investigation, which was mainly undertaken for the purpose of verifying the reported 

 existence of the diamond in the Canon Diablo meteorite, nothing resembling that substance, or any other form of free 

 carbon, could be detected, it was suspected that possibly the polishing effect produced by the dissolved mass and 

 attributed to the presence of diamond dust might be due to schreibersite. Owing to the minuteness of the grains 

 and their extreme brittleness, it is difficult to determine their hardness accurately and the figures given (7.01 to 7.22) 

 may be too low. The means at hand were too crude for an accurate test, but apparently distinct scratches were pro- 

 duced on a cleavage plane of topaz and a depolishing effect on the polished face of a cut sapphire. Specimens were 

 submitted to Mr. George F. Kunz with a request to test the hardness with more perfect appliances. 



The nonmagnetic residue consisted for the most part of irregular, black, coal-like particles full of needles of rhab- 

 dite. These dissolve quietly in strong hydrochloric acid, setting free the crystals of rhabdite. In strong nitric acid 

 under the microscope there is a rapid evolution of gas that tears the particles to pieces, scattering the rhabdite and 

 leaving an extremely light, whitish flocculent skeleton. 



In the following analysis this coaly residue was treated with strong nitric acid for a few minutes until the black 

 color disappeared, and an attempt was made to collect the escaping gas. As, however, abundant red fumes appeared, 

 it was concluded that the gas came from the acid and it was allowed to escape. The great deficiency in the following 

 analysis indicates, however, that a gaseous constituent may have been set free from the substance. The heavy resi- 

 due was separated by decantation and divided with the magnet into rhabdite and nonmagnetic portion consisting of 

 rust particles and grains of sand evidently from laboratory dust, or dirt on the original rust covered surface of the 

 meteorite. Nothing of interest that could be referred to the meteorite could be observed in it under the microscope. 

 The light flocculent residue collected on an asbestus filter was burned and determined as carbon by collecting and 

 weighing the gas given off. The other constituents were determined in the nitric acid solution. The numbers given 

 below can only be considered as approximate, as the separation by decantation may not have been complete and 

 there may have been some loss in the mechanical separation of the heavy residue. Still, after making all due allow- 

 ances for defects in the process of the analysis, the deficiencies are too great to be accounted for in this manner and 

 must be attributed to one or more undetermined constituents, possibly gaseous. The result obtained is as follows: 



The phosphorus can probably be referred to a partial solution of the rhabdite and the traces of chromium may 

 perhaps indicate an admixture of daubreelite. The whitish flocculent substance giving carbonic acid on burning 

 is very extraordinary, though something similar seems to have been observed by Tschermak (as quoted by Flight, 

 History of Meteorites, p. 163) in the Goalpara meteorite. As a similar residue with the same aspect and behavior 

 with acids and with strong nickel reaction in the borax bead was obtained in small quantities from Bendego, efforts 

 are being made to obtain a sufficient amount for a.careful study of this curious substance. 



The nonmagnetic residue of the above analysis contained all the nonsoluble and nonmagnetic residue of the orig- 

 inal mass treated, together with all the dirt accumulated throughout the long process of treatment. Nothing of in- 

 terest that could not be referred with almost absolute certainty to the latter source could be observed in it in a careful 

 microscopic examination. Evidently the mass treated did not contain diamonds or anything remotely suggestive 

 of them. 



Extended explorations were made at the locality by Messrs. Barringer 18 and Tilghman 20 , 

 who described their work in full. For the purposes of this catalogue an abstract given in the 

 American Journal of Science 21 may be sufficient : 



Recent papers on this Bubject by D. M. Barringer and B. C. Tilghman give a detailed description of the crater- 

 like form of Coon Butte, and reaffirm with confidence the hypothesis early suggested that it was formed by the im- 

 pact of an enormous meteorite falling with something like its original planetary velocity. As is well known, this 

 region has afforded many thousand masses of meteoric iron varying in weight from a thousand pounds and more down 

 to a few ounces, the total amount aggregating, it is stated, more than ten tons. Further, since the gentlemen above- 

 mentioned have taken possession of the property, their search has revealed several thousand additional masses, aggre- 

 gating more than a ton. The various remarkable features of the iron are too well known to need to be rehearsed here, 

 but it is interesting to note that Prof. J. W. Mallet has found both platinum and iridium in samples of residues from 

 solution in hydrochloric acid. Besides the iron, large quantities — a ton or more in weight — of magnetic oxide of iron 

 have been found distributed over the surface of the rim and the surrounding plain. This "iron shale" contains nickel, 

 iridium, and platinum, and apparently in the same proportion as in the meteorite itself, from which it is believed it 

 was derived. Similar material, consisting of magnetite in various forms, was also found within the crater at depths 

 varying from 300 to 500 feet. Part of this was in form of small spherules or "shale balls;" these showed a nucleus of 



