he can account for it by supposing the mass of Venus to be from the 10th to the 15th part greater than it is supposed to be. By admitting a possible error in the obliquity of the Ecliptic of 24", and consequently an increase of one-tenth in the mass of Venus, M. Liais asserts that the whole motion in the perihelion of Mercury may be explained; and he further asserts, that by abandoning the invariability of the mean motions, which supposes a constancy in the masses of which there is no proof, the position of Mercury may be explained without supposing so great a motion in his perihelion as has been alleged.

To this remarkable paper no reply has yet been made by Leverrier, or any French astronomer. In the Cosmos, however, of the 4th May, we find a letter of the Abbé Moigno prefixed to a reply to M. Liais, by M. Radeau, of Koenigsberg. The Abbé is justly offended at the expression of M. Liais, "that the observation of M. Lescarbault (in reference to his not having seen the entry of the spot) is partially fabricated (apres le coup), on after consideration." He considers it as dispensing him from refuting it; and he adds, that in order to leave no doubt in the matter, he cheerfully accepts the short reply of M. Radeau.

Although we have great confidence in the honesty of M. Lescarbault, and anxiously hope that he has made a great discovery, we cannot admit that Professor Radeau has, on any essential point, refuted either the assertions or the arguments of Liais. In the first place, he states, on the authority of the Connaissance des Temps, that the difference of longitude between Orgeres and San Domingos is 3h. 2m., in place of 3h., as adopted by Liais; but, as he allows that the difference of parallaxes would have retarded the entry of the planet only about half a minute at San Domingos, he admits the great fact, that the planet ought to have appeared on the Sun's disc during the eleven minutes that M. Liais was surveying it. He then asks if M. Liais may not have made the interval of his observations-namely, 12h. 42m. to 1h. 17m.-too wide, so as to permit us to reduce these fatal eleven or twelve minutes, as he calls them, and keep the planet so much nearer the margin of the disc as to escape the notice of Liais, whose observation he considers as simply a negative one that proves little. To this M. Liais will doubtless reply, that the limit of 1h. 17m. was the limit recorded in two notes, and must therefore be held as

correct.

M. Radeau then replies to the argument, that in consequence of Vulcan's superior brightness to Mercury he ought to have been seen near the Sun. Liais himself had seen Mercury within 1° of the Sun on the 14th July 1858, and with the naked eye

Probability of the Rediscovery of Vulcan.

19

near the horizon, within 7° of the Sun; and therefore, a fortiori, a brighter, though a smaller planet, ought to have been often seen in the same region. In reply to this, M. Radeau says, that the distance, 0-1427, at which he finds Vulcan's brightness to be 7.36 times that of Mercury, is not the result of M. Lescarbault's observation, as he says it is, and that we may, without inconvenience, suppose it equal to 0-22; and the true distance of Mercury being 0-33 on the day mentioned, the ratio of their distances will be as 2 to 3, and the ratio of their brightness as 9 to 4-that is, as 2-25 to 1, in place of 7-36 to 1. "Hence," continues M. Radeau, "the total light emitted by Vulcan will be only one-half, in place of double that of Mercury, on the supposition that Mercury has a disc four times greater than that of Vulcan."

The assumption of 0.22 as the distance of Vulcan, is, we must say, wholly unjustifiable. Liais's number, 0.1427, is that which Leverrier has deduced from Lescarbault's observations; and Radeau himself, in his first paper, actually makes it, as we have seen, 0.1423, though he afterwards reduces it. It is, therefore, unfortunate that he should not have at least mentioned this important fact. His other argument, that Mercury must always be less full, at the same distance from the Sun, than Vulcan, though true, has no real bearing on the question; for Mercury has been very distinctly seen, and Vulcan not, when the latter was more full than the former.

Since the first notice of the discovery of Vulcan, in the beginning of January 1860, the Sun has been anxiously observed by astronomers; and the limited area round him in which the planet must be, if he is not upon the Sun, has doubtless been explored with equal care by telescopes of high power, and processes by which the Sun's direct light has been excluded from the tube of the telescope as well as the eye of the observer; and yet no planet has been found. This fact would entitle us to conclude that no such planet exists, if its existence had been merely conjectured, or if it had been deduced from any of the laws of planetary distance, or even if Leverrier or Adams had announced it as the probable result of planetary perturbations. If the finest telescopes cannot rediscover a planet that has a visible disc, with a power of 300, as used by Liais, within so limited an area as a circle of 16 degrees, of which the Sun is the centre, or rather within a narrow belt of that circle, we should unhesitatingly declare that no such planet exists; but the question assumes a very different aspect when it involves moral considerations. If, after the severe scrutiny which the Sun and its vicinity will undergo before, and after, and during his total eclipse in July, no planet shall be seen; and if no round black

spot, distinctly separable from the usual solar spots, shall not be seen on the solar spots, we will not dare to assert that it does not exist. We cannot doubt the honesty of M. Lescarbault; and we can hardly believe that he was mistaken. No solar spot, no floating scoria, could maintain, in its passage over the Sun, a circular and uniform shape; and we are confident that no other hypothesis but that of an intra-mercurial planet can explain the phenomena seen and measured by M. Lescarbault-a man of high character, possessing excellent instruments, and in every way competent to use them well, and to describe clearly and correctly the results of his observations. Time, however, tries facts as well as speculations. The phenomenon observed by the French astronomer may never be again seen, and the disturbance of Mercury which rendered it probable, may be otherwise explained. Should this be the case, we must refer the round spot on the Sun to some of those illusions of the eye or of the brain, which have sometimes disturbed the tranquillity of science.

Dr Brown's Life and Works.

21

ART. II.-1. Funeral Sermons, preached on occasion of the Death of John Brown, D.D. By A. THOMSON, D.D., and JAMES HARPER, D.D.

2. Memoir of John Brown, D.D. By JOHN CAIRNS, D.D. 3. Analytical Exposition of the Epistle to the Romans. One

vol. 8vo.

4. Discourses and Sayings of Our Lord Jesus Christ. Illustrated in a Series of Expositions. Second edition. 3 vols. 8vo. 5. Expository Discourses on the First Epistle of Peter. Second edition. 2 vols. 8vo.

6. Parting Counsels: An Exposition of Second Peter, First Chapter. With Four Additional Discourses. 8vo.

7. Exposition of the Epistle to the Galatians. 8vo.

8. Resurrection of Life: An Exposition of First Corinthians XV. With a Discourse on Our Lord's Resurrection. 8vo. 9. Sufferings and Glories of the Messiah Signified Beforehand to David and Isaiah: An Exposition of Psalm XVIII. and Isaiah LII. 13–LIII. 12. 8vo.

10. An Exposition of Our Lord's Intercessory Prayer; with ‹ Discourse on the Relation of Our Lord's Intercession to the Conversion of the World. 8vo.

11. Discourses suited to the Administration of the Lord's Supper. Third edition, 8vo.

12. Hints on the Lord's Supper, and Thoughts for the Lord's Table. Foolscap 8vo.

13. Hints to Students of Divinity. Foolscap 8vo.

14. Strictures on Mr Yates' Vindication of Unitarianism. 8vo. 1814.

15. On Religion, and the Means of Attaining it. Sixth edition. 18mo. 1818.

16. Statement of the Claims of the British and Foreign Bible Society on the Support of the Christian Public. With an Appendix. 8vo. 17. The Law of Christ respecting Civil Obedience, Especially in the Payment of Tribute; with an Appendix of Notes: to which are added Two Addresses on the Voluntary Church Question. Third edition.

8vo.

18. Comfortable Words for Christian Parents Bereaved of Little Children. Third edition. 18mo. 1858.

19. Plain Discourses on Important Subjects. Foolscap 8vo. 20. The Dead in Christ, and their Present and Future State 18mo.

21. Revival of Religion: What it is, and how to be Attained and Manifested. 18mo. Third edition.

22. The Three Gatherings. 18mo.

23. Theological Tracts, Selected and Original. 12mo. 3 vols. Edited by John Brown, D.D. 1853, etc.

24. Of the Light of Nature. A Discourse by Nathanael Culverel, M.A. Edited by John Brown, D.D. 1857.

THIS long list of books, great and small, learned and popular, exegetical and doctrinal, experimental and polemical, tracts for the times and discussions on truths of permanent moment, proves their author to have been, at least, a busy man. But when it is borne in mind that he was, during the period of this prolific production, pastor of a very large congregation in Edinburgh, doing constant duty, and liable to perpetual interruptions, teaching "publicly and from house to house," occupied also with ecclesiastical matters, and bearing his part in such religious and benevolent associations as every great city sustains, the preceding catalogue shows him to have been a man of incessant and extraordinary labour. Nor was it with Dr Brown as with men of an earlier period, who seem to have published all they wrote as a thing of course; for large stores of his manuscripts remain behind, not in the shape of note-books, discourses, meditations, or diaries jotted down at sundry times," but treatises and commentaries, formally and finally prepared for the press. Nor are these books named at the head of this article collections of sermons first preached, and then cunningly remoulded and thrown into printed circulation. Each of them has a specific object,―is the elaborated defence of some truth, or the definite exposition of some book of Scripture. We could name several series of popular books, both practical and prophetic, which resemble stucco images flung out of the same mould, all very like, but none of any value, and scarce to be distinguished from one another by some slight variations of feature or attitude. But Dr Brown's works are like a gallery of statues, in which, indeed, you may see the style and mannerism of the same hand; but each piece has a history, unity, individuality, and purpose of its The mere ambition of authorship did not move him to this fertile diligence-it was not in youth, but in age, when he was midway between sixty and seventy, that he published the majority of his works-not to let the world see what he could do, or what he had been doing, and what now was the harvest of his life. No; he employed the press, as solemnly and prayerfully as he had used the pulpit, for the work of his Master, the welfare of the Church, and the service of the age. And he had been in no haste to assume the responsible task-one of his finished Expo

own.