M. Haidinger on the Original Formation of Aerolites. 443 



arduous task. It must not be forgotten that there are two cos- 

 mical or planetary bodies in question ; the one a large one (our 

 own globe), and a comparatively minute one (the meteorite). 

 M. Leverrier, to whose talents and genius as an astronomer and 

 mathematician we chiefly owe the discovery of the planet Nep- 

 tune, felt himself authorized to pronounce, before the Paris Aca- 

 demy (October 1, 1860), a view or suspicion which he himself 

 designates as " strange at the first aspect, but very possibly a 

 reality*," viz. that in comparatively recent times new and small 

 planets have been formed out of planetary matter existing at 

 different distances around the sun, and possessing various de- 

 grees of density and volume f, but that their existence had 

 remained unperceived till, during the last few years, the extra- 

 ordinary amount of attention bestowed on the subject had at 

 length been rewarded by a number of discoveries J. 



The original formation and constitution of cosmical bodies have 

 of late become the subject of the most diversified consideration. 

 Some have tried to develope peculiarities previously more or less 

 neglected; others (as my respected friend Prof. C. F. Naumann, 

 in his classical ' Manual of Geology/ chapter on the Temperature 

 of the Interior of the Globe, 2nd edit. 1857, vol. i. p. 36) have 

 endeavoured to treat the question in a lucid and exhaustive 

 synopsis, and to collect into a whole the opinions of men of the 



* " Une idee, un soupcon, etrange peut-etre au premier abord, mais qui 

 peut tres-bien etre une realite." — Moigno's Cosmos, 1860, vol. ix. p. 476. 



t " L'espace autour du soleil est, on le sait, rempli de matiere cosmique, 

 et de matiere cosmique de tous degres de tenuite et de grosseur." — Ibid. 



t As closely related to tbis portion of M. Haidinger's paper, tbe following 

 extract from the ' Annual Register of Facts and Occurrences ' for August 

 1861, may be here appropriately inserted: — "M. Leverrier, from the per- 

 turbations observed in the orbits of the planets Mercury, Venus, the Earth, 

 and Mars, has still more recently come to the conclusion that there exists 

 in our own system a considerable quantity of matter which has not hitherto 

 been taken into account. In the first place, he supposes that there must 

 exist within the orbit of Mercury, at about 0' 1 7 of the Earth's distance from 

 the Sun, a mass of matter nearly equal in weight to Mercury. As this 

 mass of matter would probably have been observed before this, either in 

 transit over the Sun's disc, or during total eclipses of the Sun, if it existed 

 as one large planet, M. Leverrier supposes that it exists as a series of aste- 

 roids. Secondly, M. Leverrier sees reason to believe that there must be a 

 mass of matter, equal to about one-tenth of the mass of the Earth, revol- 

 ving around the Sun at very nearly the same distance as the Earth. This 

 also he supposes split up into an immense number of asteroids [? meteo- 

 rites]. Thirdly, M. Leverrier's researches have led him to the conclusiou 

 that the group of asteroids which revolve between Mars and Jupiter, sixty 

 of which have already been seen and named, and had their elements deter- 

 mined, must have an aggregate mass equal to one-third of that of the 

 Earth. He likewise thinks it is not unlikely that similar groups of aste- 

 roids exist between Jupiter and Saturn, Saturn and Uranus, and between 

 Uranus and Neptune." See also Cosmos for June 1861, p. 639. — R. P. G. 

 2G2 



