34 BULLETIN 149, UNITED STATES NATIONAL MUSEUM 



die geshicbartigen Knollen iind Kugeln darin, keine einfach nachen 

 Bestantheile, sondern nichte anderes sind als auch wie die Meteoriten. 

 Meteoriten nur von anderer Anordung ein und derselben naturn 

 Bestandtheile." And again: "Es sind also die Einschlusse theils 

 kleine meteoriten, theils Triimmer von meteoriten von holienen Alter 

 als diejenigen meteoriten es sind, in welche sie eingeschlossen vori<:om- 

 men; es sind altere kleinere meteoriten in jungerern grossern mete- 

 oriten." In brief, and in plain English, he believed each particle as 

 now found to represent a minute but independent meteorite derived 

 from the breakmg up of some older preexisting stone and now in- 

 cluded as a constituent part of one new formed. 



In discussing the microscopic structure of meteoric stones, H. C. 

 Sorby, in 1864 ^^ wrote: 



It would, therefore, appear that after the material of the meteorites was 

 melted, a considerable portion was broken up into small fragments subsequently 

 collected together, and more or less consolidated by mechanical and chemical 

 action. * * * Apparently this breaking up occurred in some cases when the 

 melted matter had become crystalline, but in others the form of the particles 

 lead me to conclude that it was broken up into detached globules while still 

 melted. This seems to have been the origin of some of the round grains met with 

 in meteorites; for they occasionally still contain a considerable amount of glass, 

 and the crystals which have been found in it are arranged in groups radiating 

 from one or more points on the external surface in such a manner as to indicate 

 that they were developed after the fragments had acquired their present spheroidal 

 shape. 



In continuation of this same idea in 1877,^^ Sorby wrote: 



As is well known, glassy particles are sometimes given off from terrestrial 

 volcanoes, but on entering the atmosphere they are immediately solidified and 

 remain as mere fibers, like Pele's hair, or as more or less irregular laminae, like 

 pumice dust. The nearest approach to the globules in meteorites is met with in 

 some artificial products. By directing a strong blast of hot air or steam into 

 melted glassy furnace slag, it is blown into a spray, and usually gives rise to 

 pear-shaped globules, each having a long, hair-like tail, which is formed because 

 the surrounding air is too cold to retain the slag in a state of perfect fluidity. 

 Very often the fibers are of the chief product. I have never observed any such 

 fibers in meteorites. The formation of such alone could not apparently occur 

 unless the spray were blown into an atmosphere heated up to near the point of 

 fusion, so that the glass might remain fluid until collected into globules. The 

 retention of a true vitreous condition in such fused stony material would depend 

 on both the chemical composition and the rate of cooling, and its permanent 

 retention would in any case be impossible if the original glassy globule were 

 afterwards kept for a long time at a temperature somewhat under that of fusion. 

 The combination of all these conditions may very well be looked upon as unusual, 

 and we may thus explain why grains containing the glass are comparatively 

 very rare; but though rare they point out what was the origin of many others. 

 In by far the greater number of cases the general basis has been completely 

 devitrified, and the larger crystals are surrounded by a fine-grained stony mass. 



•' Proc. Royal Soc, June, 1864. 



«9 Nature, London, April 5, 1877, p. 296. 



