222 SPECIAL EESTJLTS IN THE URANOLOGICAL 



century, to undertake a more careful examination of the 

 nebula) of Andromeda and Orion. He thought that he 

 perceived changes in the latter since the time of Huygens : 

 and that he even discerned in the nebula in Andromeda 

 " stars which cannot be seen with less powerful telescopes." 

 We have reason to believe that he was mistaken in regard to 

 the supposed alterations in the nebula in Orion, but since 

 the remarkable observations of George Bond the same 

 cannot altogether be said in regard to the existence of stars 

 in the nebula in Andromeda. Cassini, it should be re- 

 marked, was from theoretic grounds disposed to anticipate 

 such a resolution, since (in direct contradiction to Halley 

 and Derham), he considered all nebulae to be very remote 

 clusters of stars ( 372 ). It is true that he looked upon the 

 faint milky lustre of the object in Andromeda as analogous 

 to that of the zodiacal light, but this last was also regarded 

 by him as composed of a countless multitude of small plane- 

 tary bodies thickly congregated ( 373 ). 



Lacaille, during his sojourn in the southern hemisphere 

 (at the Cape of Good Hope, and the Isles of France and 

 Bourbon, 1750 1752), augmented the number of observed 

 nebulae so considerably that, as has justly been remarked by 

 Struve, " through this traveller's labours more was then 

 known of the nebulae of the southern heavens than of those 

 visible in Europe." Lacaille moreover attempted not un- 

 successfully to arrange the nebulae into classes according to 

 their apparent forms ; he also first undertook, although with 

 little result, the difficult analysis of the two Magellanic 

 clouds (Nubecula major et minor) with their heterogeneous 

 contents. 



If we deduct from the other 42 isolated nebulae which 



