TRANSACTIONS OF THE SECTIONS. 15 



In briefly alluding to the origin of meteorites, I consider it now almost univer- 

 sally admitted by the highest authorities, that, mineralogically speaking, aerolites 

 falling to the earth are merely fragments of larger rocks, some of which may be 

 considered to be strictly volcanic : whether stone or iron, they enter our atmosphere 

 as in-egular-shaped fragments, which may again become broken into smaller frag- 

 ments before reaching the surface of the earth. In explaining the original_ or 

 " naacent " state of meteoric matter as he does, M. Haidinger is simply proposing 

 a new theory to account for the original condition of planetary matter and its con- 

 solidation ; and whether that was fluid or gaseous, or pulvende)it, may perhaps be 

 a step too remote for the present state of aerolitic investigation ; though whether 

 then- present condition will thi-ow additional light on the physical history of our 

 own earth, or the reveree, I am not prepared at present to say. The idea that 

 meteoric stones are fragments of a larger and broken-up mass of planetary matter, 

 itself originally formed', as I understand it, by the external consolidation, by gi-avi- 

 tation, of fine impalpable dust, in the form of an external crust (or series of con- 

 centric crusts), internally conti-acting somewhat after the manner of septaria, and 

 aftei-wards, fi-om heat, chemical action, unequal expansion, bm-sting like a projectile 

 filled with explosive material, is certainly a bold idea, and I only regi-et that M. 

 Haidiuger's abstract of his original paper does not more fully give all his facts, 

 comparisons, and argmnents. To my own mind, however, the idea of an original 

 state of tine planetary dmt is not satisfactoiy ; for dust rather implies the notion of 

 waste, or wear and teai* of matter already pre%'iously consolidated. 



However originally fonned, oiu- meteoric planet may in the course of time be 

 supposed from some cause or other to become broken up into fragments more or 

 less dispersed, and occasionally, in the form of aerolites, to come into contact with 

 our own earth. This may be all the more probable, when I add that I hear that 

 M. Leverrier has qiute receatly come to the conclusion that there exists " a mass 

 of matter equal to about ^^th of the mass of the earth revolving roimd the sun at 

 veiy nearly the same mean distance as the earth, and which is probably split up 

 into an immense number of small asteroids." (See Monthly Register of Facts for 

 August 1861.) 



The sti-uctm'e, composition, and specific gi'avity* of meteorites agree very closely 

 with that of similar rocks on bur own globe ; and it may not be unreasonable to 

 suppose that the former are representatives of that mysterious planetaiy matter, of 

 whose aggregate mass M. Leverrier has just informed us, and which in the course of 

 ages, at the rate of several thousand tons annually, may eventually be all absorbed, 

 as Eeichenbach has suggested, by our own earth. 



An attempt to account for the Physical Condition and the Fall of Meteorites 

 upon our Planet. By W. HAiDryGEE, Eon. Mem. B.S. L. Sf E., H.F.E.G.S., 

 F.F.G.S., H.M. SS. of Cambridge, Manchester, Edinburgh, Truro, 6fc. 



I beg leave to lay before the British Association for the Promotion of Science, 

 the outline of some considerations which have been impressed on my mind during 

 late studies in this most interesting department of physical science, and one which 

 is still involved in many difficulties and contradictions. 



In order to give a more general view of the present state of progTess, I mention 

 the names of some of the more active promoters of the science in om* own days. 

 The Imperial Collection at Vienna, which took the lead under v. Schreibei-s and 

 Partsch, is still foremost imder Dr. Homes, but closely followed by Prof Shepard 

 in New Haven ; Baron Reichenbach in Vienna ; the British Museum under the en- 

 lightened superintendence of Mr. Nevil Stoiy Maskelyne ; Pi'of Gustavus Rose in 

 Berlin ; Prof. Wohler in Gottingen ; Mr. R. P. Greg in Manchester, — each pos- 

 sessing fi'om 100 to 163 meteorites with distinct dates of fall or discovery ; to the 

 labours of the above-named, add also those of Rammelsberg, Lam-ence Smith in 

 Louisville, Kentiicky, 0. Buchner in Giessen. The recent remarkable fixlls of 

 aerolites near New Concord, and in Guernsey County, Ohio, on the 1st of May, 

 and near Dharamsala, KangTa, Pimjab, on the 14th of July, both in 1860, the 



* The iron masses that occasionally fall are supposed by M. Haidinger veiy reasonably 

 to have originally existed as veins in the original meteoric planet. 



