300 REPORT 1881. 



stone to the National Collection, and for ultimate examination and 

 analysis. 



The interior of the Middlesbrough aerolite exhibits a perfectly uniform 

 strncture and greyish-white appearance, spangled with frequent metallic 

 iron-grains and crystals of iron -sulphide. A few isolated spherules of 

 white homogeneous material, apparently identical with the cementing 

 substance of the mass, and as large as hemp-seeds, occur at intervals, but 

 these well-formed 'chondra,' as they are termed, appear in this aerolite 

 to be rather large than very plentiful. 



Round some of the iron-grains oxidation has caused rnsset-brown 

 coloration of the neighbouring white mineral, in spots with which the 

 sawn face and broken surfaces are all pretty freely speckled over. The 

 ground-mass itself is a fine-grained assemblage of nearly colourless 

 crystals cohering together pretty firmly with little intervening paste. 

 Under the microscope a few of the larger crystals are clear and trans- 

 parent, while the general aggregation of the finer ones is confused and 

 turbid.^ In some compactor areas, which may be paste or spherule- 

 sections, tangled dendritic markings (perhaps indicative of the presence of 

 manganese) spread from centres apparently of iron-gi-ains, and by their 

 arborescence and coralline appearance recall the recently published an- 

 nouncements by Dr. Hahn, of his microscopical observations of fossil 

 forms and vestiges of organisations in the spherules of aerolites. The 

 analysis of the Middlesbrough aerolite, which has not yet been executed, 

 Avill be particularly interesting if it reveals in the metallic substance 

 traces of manganese, and also if it succeeds in identifying tlie kind of 

 silicate of which the stony substance of the meteorite seems to be almost 

 unifoi'mly composed. The substance in powder, as was ascertained with 

 a very small trial of its dust, phosphoresces pretty brightly by heat when 

 thrown on a hot iron in the dark. As this property of phosphorescent 

 minerals, it is known, can only be restored to them after its loss by heat, 

 either by strong and long-continued insolation or by subjecting them to 

 strong electrical discharges, the question of the original habitat, and of 

 the original separation or ejection of meteoi-ites from foreign planets, .suns, 

 or comets will perhaps be narrowed in some measure by observations of 

 this property in other meteorites besides that of Middlesbrough, in some 

 of which the character of phosphorescence by heat may perhaps be shown 

 by trials to be equally distinct. 



Among known stonefalls, of which specimens are preserved, the 

 nearest congeners in date with that of Middlesbrough, are Sales (France), 

 1798, March (8 ?) or 12, 6 p.m., 20 lbs., 3-45 sp. gr. ; Alais (France), 

 1806 March 15, 5 p.m., 8 -+- 4 lbs., W. to E., 1-70 sp. gr. (carbonaceous) ; 

 Timoschin (Russia) 1807, March 13, aftn., 160 lbs., 3-64 sp. gr. ; Kule- 

 schowka (Russia), 1811, March 12, night, 13 lbs. + 9 lbs. (?), 3-49 sp. gr. ; 



' 'Sir. T. Davies, of the Dritisb ]Museum, "Mhieralogical Department, has quite 

 recently oblig-ed the Committee, in anticipation of the meteorite's chemical analysis 

 by Dr. Flight, with some observations of its visible characters and composition. The 

 substance of his remarks extracted frorh the timely communication in which he was 

 so good as to notify them to the Committee, is added as a postscript to tliis account. 

 While it renders unnecessary and superfluous some of the details which follow here 

 of the meteorite's internal appearance, it will also be seen to correct and clear up 

 some of the surmises offered regarding the occurrence of microscopic simulations, or 

 • dendrites ' in the i\Iiddlesbroiigh aerolite, and regarding the possible astronomical 

 connection of that aerolite with the Sales and Kuleschowka ones. 



