Every increase of power, while it resolves nebulæ hitherto unresolved, at the same time descries new ones defying resolution. It may be argued that, possibly, some of these may consist of genuine nebulous matter; but the question is not one of possibility but probability, and the revelations of the telescope have reduced such probability to its lowest point. The different degrees of apparent condensation, are explained by the various ways in which the stars are arranged in these clusters. Sometimes they appear to be pretty equally distributed, but at others there is a rapid concentration, so that at an unresolvable distance, the appearance is that of a single star surrounded by a nebulosity. The actual changes alleged to have been observed in these nebulte, are ascribed to the difference of appearance presented by telescopes of different optical power; features being brought into view by very powerful telescopes, which are altogether invisible in telescopes of inferior power. But though change were established, it would only refer to a difference in the aggregation of distinct stars, not in the chemical condensation of nebulous matter. The existence of anything like nebulous matter in space, is now only countenanced by the constitution of comets, the new ring of Saturn, the zodiacal light, and the zones of meteoric matter. The existence of nebulæ in the process of condensation, can no longer be used in support of the nebular hypothesis. The result then of the whole is, that as a purely mechani-
