﻿2G0 Chevalier W. von Haidinger on the Luminous, Thermal, 



ments thus : " The anterior portion of our meteorite is charac- 

 terized beyond any doubt by the presence and the direction of the 

 seams of enamelled crust, by means of which the position of the 

 stone during its telluric course before its fall may be ascertained." 

 According to Dr. vom Rath (p. 6) the meteorites of Pultusk 

 cannot be considered to be the results of the diffraction of one 

 single cosmical body, but must rather be supposed to be a swarm 

 of larger or smaller planetary individuals that had come within the 

 sphere of terrestrial attraction and having most of them under- 

 gone diffraction, although the strongly flattened cosmical figure 

 could still be traced on some of them. As von Haidinger re- 

 marks, seams of enamelled crust could not be formed on meteo- 

 rites of quite irregular form, whose position necessarily changes 

 at every moment of their course. During its cosmical course 

 a swarm could remain in repose ; but as soon as it enters the 

 terrestrial atmosphere, the individuals composing it, in collision 

 with each other, must undergo loss of substance. During the 

 continuation of the cosmical course through the atmosphere, the 

 conditions for incrustation constantly remained extant, and frag- 

 ments of secondary origin could be incrusted again. From 

 the moment of detonation the incrusted meteorites, having 

 reached their point of dispersion, fall down individually in more 

 or less vertical direction ; they may thus damage each other, 

 but no new incrustations take place. Figs. 7 a and 7 b in Dr. 

 vom Rath's paper (p. 9) deserve particular attention, represent- 

 ing a completely incrusted meteorite with an aggregation of 

 thirty to forty minute fragments which had evidently adhered 

 to it during its course when its velocity began to suffer diminu- 

 tion. An analogous circumstance has been observed by von 

 Haidinger on a meteorite from Stannern ; it is, however, cha- 

 racteristic of those from Pultusk. Dr. vom Rath says, further, 

 (p. 27), "The meteorites, not quite dissimilar to telluric rocks, 

 although for the most part so different from them, indicate con- 

 ditions of formation as they were never found united within the 

 known portion of the terrestrial crust;" and (p. 12), "The ex- 

 planation of the surfaces clothed with metallic or sulphuretted iron 

 (metallische Harnische) presents great difficulties; at all events, 

 they are of cosmical origin, while the lines and surfaces of fusion 

 are of telluric origin." This last assertion appears to von Hai- 

 dinger not to be quite unobjectionable. The enamelled crust, 

 formed during the course, . may, under peculiar circumstances, 

 penetrate here and there into the substance of the meteorite ; it 

 must, however, be admitted that the internal clefts and fissures, 

 partly filled up with a black enamel-like substance, have origi- 

 nated during the cosmical period of the mass, before its being- 

 broken into pieces which immediately began their course through 



