Something analogous to this one may see in the distributions of literature and science. Many popularize and diffuse: some reap and gather on their own account. Many translate, into languages fit for the multitude, messages which they receive from human voices: some listen, like Kubla Khan, far down in caverns or hanging over subterranean rivers, for secret whispers that mingle and confuse themselves with the general uproar of torrents, but which can be detected and kept apart by the obstinate prophetic ear, which spells into words and ominous sentences the distracted syllables of ærial voices. Dr. Nichol is one of those who pass to and fro between these classes; and has the rare function of keeping open their vital communications. As a popularizing astronomer, he has done more for the benefit of his great science than all the rest of Europe combined: and now, when he notices, without murmur, the fact that his office of popular teacher is almost taken out of his hands, (so many are they who have trained of late for the duty,) that change has, in fact, been accomplished through knowledge, through explanations, through suggestions, dispersed and prompted by himself. For my own part, as one belonging to the laity, and not to the _clerus_, in the science of astronomy, I could scarcely have presumed to report minutely, or to sit in the character of dissector upon the separate details of Dr. Nichol's works, either this, or those which have preceded it, had there even been room left disposable for such a task. But in this view it is sufficient to have made the general acknowledgment which already _has_ been made, that Dr. Nichol's works, and his oral lectures upon astronomy, are to be considered as the _fundus_ of the knowledge on that science now working in this generation. More important it is, and more in reconciliation with the tenor of my own ordinary studies, to notice the philosophic spirit in which Dr. Nichol's works are framed; the breadth of his views, the eternal tendency of his steps in advance, or (if advance on that quarter, or at that point, happens to be absolutely walled out for the present,) the vigor of the _reconnoissances_ by which he examines the hostile intrenchments. Another feature challenges notice. In reading astronomical works, there arises (from old experience of what is usually most faulty) a wish either for the naked severities of science, with a total abstinence from all display of enthusiasm; or else, if the cravings of human sensibility are to be met and gratified, that it shall be by an enthusiasm unaffected and grand as its subject. Of that kind is the enthusiasm of Dr. Nichol. The grandeurs of astronomy are such to him who has a capacity for being grandly moved. They are none at all to him who has not. To the mean they become meannesses. Space, for example, has no grandeur to him who has no space in the theatre of his own brain. I know writers who report the marvels of velocity, &c., in such a way that