Or THE PLANET NEPTTTUE. 425 



repealed the unseen, yet known planet, to the eye of astronomers, 

 the reviewer thus proceeds : — 



" There are two facts connected with the newly-discovered planet, 

 — the one certain, and the other all but certain, which merit par- 

 ticular attention. The first of these is its deviation to a far greater 

 extent than any one of those bodies heretofore known, from what is 

 known as Bode's law of the distances. According to this law — or 

 rather rule, seeing it simply expresses a fact of which no explanation 

 whatever can be given, — the various planets are placed at distances 

 bearing a certain and uniform relation to each other : this proportion 

 being that, the interval between Mercury and Venus being assumed 

 as uuity, the intervals between the successive orbs each double upon 

 the one before it. Had the newly -discovered orb conformed to this 

 rule, it would have been found at a distance of 3,600,000.000 miles 

 from the sun. Its actual distance is about seven-ninths of this 

 amount. And such a deviation, important and interesting in itself, 

 as the first example of departure from a rule hitherto found univer- 

 sal, derives additional interest from the fact, that, chiefly on it, con- 

 jectures have already been founded relative to the possible existence 

 of a second unknown orb, situated as much beyond the distance in- 

 dicated by the law, as the present one falls within it. This con- 

 jecture, however, must be left to time to verify. It is more than 

 probable that, if such an orb exist, the means which have guided our 

 telescopes with such unerring aim towards this one, must again be 

 employed for its discovery : its disturbing action be watched and 

 waited for; and direct observation, almost powerless at such a dis- 

 tance, be guided and led out by theory towards a mind-seen result. 



" The second of the two facts we have referred to is one of yet 

 higher interest and importance, and certainly one more unexpected 

 still. It is believed that the planet is self-luminous. This inference 

 has been deduced from its high degree of visibility and great clear- 

 ness of light, not only as compared, or rather contrasted with Uranus, 

 but beyond what is comprehensible in conformity with the known 

 principles of optics. It is, indeed, conceivable, that the physical 

 organisation of the orb may be such, as shall give to its surface a 

 tight-reflective power very far beyond all we have experience of, at 

 least among the other orbs of the system ; but it is very questionable 

 whether any amount of this, within the limits of probability, would 

 account for a planet receiving little more than a third of the sun- 

 light which Uranus ret eives, nearly equalling it in visibility, and far 

 surpassing it in vividness of light. Here, too, at all events, we are 

 called on to ' stand still and see' : to rid the mind of every bias, and 



