140 REPORT — 1865. 



" Some of the minerals in meteorites, usually considered to be the same as those 

 in volcanic rocks, have yet very characteristic differences in structure (Stannern), 

 which I shall describe at greater length on a future occasion. I will then also 

 give a full account of the microscopical structure of meteoric iron as compared 

 with that produced by various artificial processes, showing that under certain con- 

 ditions the latter may be obtained so as to resemble very closely some varieties of 

 meteoric origin (Newstead, &c). 



" There are thus certain peculiarities in physical structure which connect meteo- 

 rites with volcanic rocks, and at the same time others in which they differ most 

 characteristically, — facts which I think must be borne in mind, not only in forming 

 a conclusion as to the origin of meteorites, but also in attempting to explain volcanic 

 action in general. The discussion of such questions, however, sbould, I think, be 

 deferred until a more complete account can be given of all the data on which these 

 conclusions are founded." 



(8.) Note on the preceding Articles (5) and (7). By Professor Brayley. 



My friend Mr. Sorby, having resumed his microscopical investigation of the 

 structure of meteorites, privately printed and circulated a note, dated July 1865, 

 " On the Physical History of Meteorites," in which lie gives in a concise form what 

 he terms " a provisional theory " of their formation, announcing also his intention 

 to " describe the facts upon which it is founded," and discuss the " objections to 

 this and other theories in a [future] communication to the Royal Society." The 

 reception of an impression of this note from Mr. Sorby occasioned me to print, also 

 for private circulation, a comparison of the physical history of meteorites as in- 

 ferred in my own communication to the Royal Society, as above (p. 132), with that 

 inferred by him from his new observations of their microscopical structure. This 

 was placed in the hands of the officers of the Association, at the Meeting at Bir- 

 mingham, but too late to allow of its being read at any of the sectional meetings. 

 The present article is a brief abstract of it, with some additions. 



Of the two most important results relative to the origin and formation of 

 meteorites obtained by Mr. Sorby, the first is stated, in his note, as follows : — 



"A most careful study of their microscopical structure leads me to conclude that 

 their constituents were originally at such a high temperature that they were in a 

 state of vapour, like that in which many now occur in the atmosphere of the Sun, 

 as proved by the black lines in the solar spectrum." 



As original induction from observed facts, this is in reality a verification, to an 

 important extent, of the hypothesis of the origin and formation of meteorites an- 

 nounced in my paper. But I had already arrived at, and made public in that paper, 

 exactly the same conclusions, with the addition that this vapour had actually been a 

 part of the same mass, and was identical in origin, with that forming the atmosphere 

 of the Sim, constituted as we believe it to be, on the authority of Kirchhoff and the 

 other spectroscopists who have continued and repeated his researches (p. 132). 



Some of Mr. Sorby's subsequent conclusions are also closely parallel to my own. 

 " On cooling," he continues, " this vapour condensed into a sort of cometary cloud, 

 which was in a state of great commotion." This "cometary cloud" is manifestly 

 identical in nature with the bubbles or volumes of gaseous matter consisting of 

 the vapours of metallic and other elementary substances, which, having undergone 

 a certain amount of condensation, are conceived by me to be projected from the 

 Sun and through the Zodiacal Light ; and their gaseous contents having constituted, 

 according to my views, the torrents causing the phenomena termed the solar- 

 spots, in the stupendous ebullition of the photosphere, they must necessarily be " in 

 a state of great commotion," which would be retained long after their projection 

 from the Sun. 



Mr. Sorby finally concludes " provisionally that meteorites are records of the 

 existence in planetary space of physical conditions more or less similar to those now 

 confined to the immediate neighbourhood of the Sun," at a remote cosmical period ; 

 a conclusion which he identifies with " a modified nebular hypothesis." 



These physical conditions of planetary space at a former period are those which 



I attribute to the interior regions of the Zodiacal Light as existing now, and of the 



actual nature of which meteorites may be regarded as perpetual records. But I 



. believe it may be shown, by a strict process of reasoning, that one of the necessary 



