286 Nebulae. 



perturbations which it would undergo, such a termination was 

 not to be foreseen. But, considering the multitude of minor 

 planets (now amounting to 89), and the probability that their 

 number is by no means exhausted, there is no extravagance 

 in the supposition that it may have encountered some such 

 member of our system, and may thus have changed alike its 

 mode of existence and of motion ; destroyed, possibly, in the 

 ordinary sense of the word, but, in the design of an omniscient 

 and omnipotent Creator, merely transmuted into some newer 

 form, not less valuable in itself, nor less conducive to the well- 

 being of the great whole. 



KEBULiE. 



We will proceed to some additional details on the subject of 

 nebulas, which could not be included in our former paper. 



Up to October, 1864, Prof. D' Arrest had carried on the 

 Copenhagen Review of Nebulas, begun in the autumn of 1861, 

 to upwards of 2500 objects, and looked forward to its comple- 

 tion after a year or two more. Of his 215 new nebulae, a few, 

 he found, had been anticipated by Ijl and the E. of Rosse. 

 32 out of them he classes as B(right), though generally re- 

 curring as F(aint) in some of his revisions, o are of Ijl's first 

 class. He speaks of 2 great groups of Nebulas in R. A. llh. 

 58m. D. N. 21°, and R. A. 12h. 53m. to 56m. D. N. 28° to 29° (in 

 Coma Berenices), neither of which had then been investigated 

 by Lord Rosse, where, under particularly favourable circum- 

 stances, he has seen an extraordinary number of unknown 

 nebulas. They are, especially in the second group, "incredibly 

 numerous and crowded, and, though extremely small, of a 

 diversity of which no idea could have a priori been formed. 

 Occasionally, in the most favourable moments, I have had the 

 very exact impression, as though the nebulas, often containing 

 only a few seconds in diameter, though intermixed with larger 

 ones — round, longish, stellar, or comet-like — lay packed to- 

 gether like oysters in a barrel." 



Of Rosse' s 35 "nebulas not found," D' Arrest had seen 12, 

 and confirmed the invisibility of 4 others. He had repeatedly 

 seen that most curious object, 55 Andromedce (Intellectual 

 Observer, vi. 448) quite clear of nebulosity subsequently to 

 Aug. 1862; and, still later, Huggins had found its spectrum 

 similar to that of other stars. "This instance," says D' Arrest, 

 " is one of the few which deserve especial attention in future." 

 It will bo readily found a little way sjy y, being of 5:^ mag., 

 and the nearest star of that magnitude in that direction. 



He has given a catalogue, up to the beginning of 1861, 

 of 50 of those most singular and suggestive objects, Double 

 Nebula*, including about -' 7 of the whole number visible with 



