Sounds like Melville: Nile Notes by George William Curtis

Curtis's chapter on "Dead Kings" reminds me of the "After Dinner" chapter in the first volume of Mardi. The one on "Memnon" naturally makes me think of Pierre, although Curtis never displays this much depth, pathos, or eloquence:

But Memnon's sculptured woes did once melodiously resound; now all is mute. Fit emblem that of old, poetry was a consecration and an obsequy to all hapless modes of human life; but in a bantering, barren, and prosaic, heartless age, Aurora's music-moan is lost among our drifting sands, which whelm alike the monument and the dirge.  --Herman Melville in Pierre; or, The Ambiguities

Then again, who does?

From the Christian Register, March 22, 1851; found in the online archives of Historical Newspapers at Genealogy Bank.

... Some of the descriptions are exquisitely beautiful, and a dreamy languor pervades the volume, which has something of the charm of a tropical climate. From the style and way of thinking, we at first thought that it might have been written by the author of Typee; but though it appears that this is not the case, we doubt if it would have been written, unless Melville had given a previous specimen of this kind of style. We are glad to see this book, but we should be very sorry if this method of writing were to prevail, or if American young men were to imagine that there was not some higher purpose in foreign travel, than the mere gratification of a taste for artistic effects. 

Published in Boston by David Reed, the Christian Register was regarded as "the leading Unitarian weekly" according to information about Unitarian Christian Journals provided on the website of the American Unitarian Conference. The 1851 masthead of the Christian Register lists five editors: J. H. Morison, E. Peabody, A. P. Peabody, J. Parkman, and F. D. Huntington.

Christian Register [Boston] - March 22, 1851