I like the idea of book reviews for really old books. It eliminates the risk that you'll get stuck writing a review of a really bad book, because, well, everybody already knows the bad ones. Of course, there's a risk that you're just writing a hagiogram about a book that everybody holds sacred.
Steve Jones' recent Wall Street Journal review of Darwin's Voyage of the Beagle is sort of like that. He emphasizes the book's strong points, especially when compared to the earthworm monograph and barnacle series:
"The Voyage of the Beagle," in contrast, sings. Its language is that of a young man intoxicated by the tropics ("To a person fond of natural history, such a day as this brings with it a deeper pleasure than he can ever hope to experience again") and careless of the risks ("Upon landing I found that I was to a certain degree a prisoner . . . a traveller has no protection beside his fire-arms"). The youthful Darwin was a master of unadorned English. He took with him more than geology textbooks: "Milton's Paradise Lost had been my chief favourite, and in my excursions during the voyage of the Beagle, when I could take only a single small volume, I always chose Milton."
In this, Jones tactfully avoids the parts of the book that detail the backwardness of "dark-coloured natives." I think many of today's reviewers would have given the book a more critical treatment. In my thinking, the book gains by being an honest portrait of its time, clearly by an extraordinary thinker -- but one whose weaknesses are displayed as well as his strengths.
Jones does a bit of retrospective analysis that deepens the current interest, focusing on Darwin's description of St. Helena. By Darwin's time, it already was home to many introduced species, mainly from England. Now, the native flora and fauna are disappearing:
Now things on St. Helena have gotten worse. The island has 49 unique species of flowering plant, and 13 of fern, all found only there. At least seven have been driven out since the arrival of men five centuries ago, two survive only in cultivation, and many more are on the edge. The last St. Helena Olive died of mold in 1994, and of the ebony thickets only two small bushes remain. Its giant earwig (at three inches, the world's largest), giant ground beetle and St. Helena dragonfly, all common in Darwin's time, have not been seen for many years. The snail seen by Darwin is now reduced to a population of about 600. The St. Helena Petrel is extinct, and just one endemic winged creature, the Wire Bird, is left, and that too is threatened.
That's the magic of revisiting naturalists' works -- things really have changed. Being able to observe those changes puts us in the position of Hipparchus, who -- comparing notes with observers hundreds of years earlier -- noticed that Spica had moved relative to the equinox. Sometimes the long-scale comparison gives us insight into processes that are not obvious from year to year.