A beautiful triple star is situated precisely on the edge of one of these nebulous masses, just where the interior vacancy forks out into two channels. A fourth nebulous mass spreads like a fan or downy plume from a star, at a little distance from the triple nebula.' Another (8 Messier), he describes as a collection of nebulous folds and masses, surrounding and including a number of oval dark vacancies, and in one place coming up to so great a degree of brightness as to offer the appearance of an elongated nucleus. Superposed upon this nebula, and extending in one direction beyond its area, is a fine and rich cluster of scattered stars, which seem to have no connection with it, as the nebula does not, as in the region of Orion, show any tendency to congregate about the stars.' Herschel gives a view, however, of the nebula and star-cluster which, it is not too much to say, is wholly irreconcilable with the opinions here expressed. Not only are the two brightest stars of the cluster placed exactly upon the elongated nucleus,' but every 'fold and mass' of the nebula is associated with a region of greater richness in the cluster.

As respects the fourth and last nebula, that of Cygnus, I may simply quote Sir J. Herschel. He describes the region as 'consisting, first, of a long, narrow, curved, and forked streak, and, secondly, of a cellular effusion of great extent, in which the nebula occurs intermixed with, and adhering to, stars around the borders of the cells, while their interior is free from nebula, and almost so from stars."'

I have already drawn out this paper to a much greater length than I had proposed, and yet seem scarcely to have entered upon my subject. Let me, instead of proceeding to treat cursorily of the remaining branches of that subject, here pause and report progress.' We have found a law of aggregation of nebula in regions removed from the Milky Way, and thus a law of contrast, which amounts in

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reality to a law of connection between nebula and the starry system. We have found that, in the southern hemisphere, this law of contrast is further exhibited in an aggregation of nebulæ over regions in which stars are wanting, and vice versâ; lastly, we have seen that over a zone of the heavens in which nebulæ are all but absolutely wanting, there is a marked aggregation of lucid stars, that on the same zone all the irregular nebulæ are collected, and that these irregular nebulæ, all occurring in regions very richly bestrewn with fixed stars, exhibit in their configuration a correspondence with the configuration of the fixed stars in the same field, which cannot be wholly accidental.

From the Student for March 1868.

A NEW THEORY OF THE UNIVERSE.

THE present century has been remarkable for the progress which has been made in all departments of astronomy. Within the solar system, within the sidereal or galactic system, and within the yet wider range ascribed to the nebular system, discoveries of the most important character have been effected. There is a singular contrast, however, between the amount of positive knowledge which has been deduced from observational labours within the solar domain, and the somewhat vague ideas which astronomers are content to hold respecting sidereal space. I shall endeavour to exhibit the fulness of this contrast, and then to point out some of the more remarkable consequences which seem to flow from modern observations within the stellar and nebular domains.

At the end of the last century astronomers recognised in the solar system a mechanism of an uniform and symmetrical character. Around a central orb they saw revolving a family of dependent globes, vast in their absolute dimensions, but minute in comparison with the massive globe which sways their movements. Amongst these bodies they saw several attended upon by yet smaller globes, forming secondary systems, which resemble in many respects the great system of which the Sun is the controlling centre. The late discovery of Uranus had led them to recognise the possibility