Back in 1594, in the very heart of the period we will be considering in the pages that follow, Sir Francis Bacon, while prescribing the essential apparatus for “a compleat and consummate Gentleman” in his Gesta Grayorum, suggested that in attempting to achieve “within a small compass a model of the universal made private,” any such would-be magus would almost certainly want to compile “a goodly huge Cabinet, wherein whatsoever the Hand of Man by exquisite Art or Engine, hath made rare in Stuff, Form, or Motion, whatsoever Singularity, Chance and the shuffle of things hath produced, whatsoever Nature hath wrought in things that want Life, and may be kept, shall be sorted and included.”

Things that want life and may be kept, indeed. Just over a hundred years later, the young Russian who would go on to become Peter the Great, then age fifteen and summering in Amsterdam, happened into the chambers of the legendary dissector and anatomist Frederik Ruysch and first fell under the thrall of the good doctor’s uncanny collection of bottled fetuses; years later, he would buy the entire collection, bringing them back to the capital he was then constructing for himself, St. Petersburg, as the core of the vast wonder cabinet that he himself had begun compiling.

Was it just chance, though, and the shuffle of things, that, almost three centuries after that, brought our protagonist, the then-seventeen-year-old Russian philology student Lena Pisetski, here, stumbling into the dusty precincts of the old czar’s largely abandoned cabinet? Whatever the reason, the astonishing marvels she visioned that silver late afternoon stayed with her. And years later, a now-accomplished documentary and fine-art photographer (in the meantime married to the German filmmaker Werner Herzog), she returned to prize them anew: both those in St. Petersburg, and other similarly flecked wonders in Vienna, Amsterdam, Leiden, Utrecht, London, Berlin, Paris, Turin, Pavia, and even Philadelphia (the incomparable Mütter!).

The resultant body of work—achingly limpid, hauntingly suspended—was recently brought together in a book, Lost Souls, and exhibited, to widespread critical acclaim, at the International Center of Photography in New York, a show that in turn proved the occasion for a conversation between Ms. Herzog and myself as part of the New York Public Library LIVE series, parts of which are adapted in what follows.

Lawrence Weschler

I. A TWINNED SIAMESE TREE

THE BELIEVER: For starters, where did you come from, and how did you come upon these things?

LENA HERZOG: Well, I was born in Russia, in the Urals, what Ian Frazier would call the wrong side of the Urals, the eastern slope—

BLVR: The Siberian side.

LH: That’s where I was born and grew up, and then,...