OBSERVATIONS OF LUMINOUS METEORS. 291 



verics of meteoric irons, and reviews the mineralogical examinations to 

 wliich they have been submitted. Besides the new mineral chromium-sul- 

 phide, or daubreelite. Dr. Laurence Smith has now observed the occurrence 

 of chromite in nodules — an entirely new character of metallic irons — in the 

 iron meteorites of Cohahuila. The structure of meteoric irons themselves 

 is undergoing microscopical examination, and evidence of the strongest 

 kind is furnished by the inspection that in many of them solidification 

 must have proceeded in the quietest conditions, with crystallisation of 

 perfect symmetry and regularity throughout their mass. Three recent 

 stone-falls are recorded — on November 4, 1879, early in May 1880, and 

 on March 14, 1881 — in India, Persia, and in England. 



Of the last aerolite, which weighed about three and a-half pounds, 

 the descent in our own country is one of special interest to the present 

 meeting of the British Association, which celebrates its fiftieth gathering 

 in the county and city of its birth, at York, from the meteorite having 

 quite recently fallen in that county. A fuller account of this stone-fall, 

 and of the aerolite itself, than that given by Dr. Flight is, from exami- 

 nations of the circumstances connected with it by Professor Herschel, 

 added in another appendix of this Report. Although no analysis of the 

 stone has yet been made, it appears, by comparison with other aerolites in 

 the collection of the British Museum, conducted with a specimen presented 

 by the North-Eastern Railway Company to the National Mineralogical 

 Collection, to be of the ordinary grey chondritic class, a class of the com- 

 monest type of aerolites, which comprises in itself at least four-fifths of 

 all the iron and stone masses which have actually been seen to fall. This 

 recent accession, therefore, to the globe's geological constituents, furnishes 

 another instance of the prevailing uniformity of meteoritic substance, 

 and of its never-failing conformity, in the great majority of aerolites, to a 

 well-marked mineralogical description which distinguishes them very 

 strikingly from ordinary terrestrial rocks. The Middlesbrough aerolite is 

 also remarkable in its outward form by the unusual distinctness of the 

 deep grooves and furrows with which it is indented by heat and attrition 

 of the air, on that rounded side or low summit of the stone which must 

 evidently have been constantly presented foremost to the action of the 

 resisting fiery atmosphere which impeded the aerolite's motion in its 

 suddenly arrested course. 



Appendix I. 



On Aerolites and Detonating Meteors. By De. Walter Flight. 



The (Butcher) Meteoric Irons of Cohahuila} 



A year or two ago attention was directed to the discovery by Dr. L. 

 Smith of daubreelite in one of these irons. He has since met with a 

 nodule of chromite in the interior of compact iron from one of these masses. 

 His attention was attracted to an enclosed nodule, the lustre of which 

 was less vitreous than that of the chromium sulphide : it was virtually a 

 black granular mass. When heated with strong nitric acid in the water, 

 bath, not the slightest impression was made upon it, thus showing that 

 it is not daubreelite. Heating it in fused sodium carbonate in no way 



" See Amer. Jour. Sc. ii. November 1871, and xvi. 1878, 270. Also these Keports, 

 vol. for 1879, p. 125. (Appendix of lieport on Luminous Meteors, by Dr. Flight.) 



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