The question, posed by one of Thomas Jefferson’s intimates would make any historian with even the feeblest pulse sit up and take note. On May 11, 1825, Thomas G. Watkins, who was one of Jefferson’s physicians, asked the 82-year-old Sage of Monticello whether he ever had “gonorrhoea.”

If so, Watkins advised “half a grain of opium with one grain of calomel every night for a few weeks.” Should the patient notice a “copper taste at the root of the tongue,” take no more mercury, “but persist in the opium.”

Sex and drugs. This can be a heady combination, not least for the intrepid presidential biographer. These tend to be subjects public figures all too rarely discuss in their letters, but Jefferson?

Guarded in many ways, our third president was perfectly forthright in letters to his daughter when describing the system of painful boils on his backside developed during a visit in 1817 to Virginia’s Warm Springs spa. He also made no secret of his reliance on opiates.

So it is not unreasonable to think Jefferson might well have answered the doctor’s question in the same spirit in which it was asked. That is, with utmost candor. Maybe he did. But if so, I have never able to locate the response, and you can be certain I tried.

Jon Kukla, author of Mr. Jefferson’s Women, concurs. “I'm sure that if I had seen a reply I'd have used it,” Kukla tells me. The “question implied the doctor's belief that it was possible” that Jefferson contracted a sexually transmitted disease, Kukla speculates, though this might simply have been “a question [Watkins] would have asked any patient with urological symptoms.”

To which the intrepid presidential biographer can only mutter: “Damn!”

As generations of historians have discovered, primary documents only rarely yield up the nuggets one hopes. There are few smoking guns. The Historian as Detective seldom wraps up his case with the debonair self-assurance of Philo Vance. Altick’s “scholar adventurers,” for the most part, don’t resemble Roy Chapman Andrews.

But they persevere, which is the important thing. Those of us who have written about Jefferson have the good fortune of much documentary material. We also confront the fact that many previous researchers have picked through these documents to write their books. Reviewers routinely note the effrontery of anyone daring to write yet another Jefferson book, defying the presumptuous and foolhardy to come up with something — anything — new to say.

And much will not be new. That is in the nature of biographies. But some of us do have something to add, and in my case, this results from an examination of documents that most writers, I believe, overlook. The repositories of Jefferson-related correspondence, at the University of Virginia but also elsewhere —the Carr-Cary Papers, the Ellen W. Coolidge Papers, the Francis W. Gilmer Papers, and on and on—contain countless letters from people who had only the slightest acquaintance with the great political events of their day.

These were distant relatives of Jefferson’s large family—meddlesome aunts, for example, and ne’er-do-well sons-in-law. Also, nosy neighbors who liked to gossip about goings-on atop the great man’s mountain. But there were as well substantial, if largely forgotten men of medicine, such as Dr. Watkins who asked Jefferson if he’d ever been clapped up, and Albemarle County lawyers, merchants and stonemasons.

Mostly, they had nothing to say about the promise of republican government, the symmetries of Palladian architecture, or the cultivation of vitis vinifera. They said a great deal, however, about everyday life at Monticello and the complicated dynamics of Jefferson’s family.

It is, of course, impossible to know exactly which scholars looked at which documents. But until Twilight at Monticello, which relied heavily on them, no one had reconstructed in such grisly detail the 1819 stabbing of Jefferson’s beloved grandson, Thomas Jefferson Randolph, by Randolph’s brother-in-law, the alcoholic Charles Bankhead. No one, to my knowledge, has noticed Jefferson’s characteristic refusal to acknowledge the emotional toll it took. In a letter to James Madison, Jefferson referred only to Randolph suffering injuries in an “accident.”

That’s only one example. The book is chockablock with such episodes, recounted as in as realistic detail as possible. These stories are told not to titillate — though some may have that effect — but to show the material realities of life at Monticello.

And there’s a reason for that. The temptation, when writing about Jefferson, is to explore the man’s ideas. Understandably so, for this is a rich area for examination. But to look at these ideas in the abstract is to be lured, as Jefferson himself was, into the world of abstraction. In this, Jefferson scholars ape Jefferson himself, which can mislead them just as it misled him.

My objective in Twilight at Monticello was to demonstrate the myriad ways in which the life of the mind can be forever interrupted by unpleasant realities. I wished to show how a man who thought of himself as a scientist (though the word would not be coined until eight years after Jefferson’s death) was himself no less a captive of the a priori as were the Platonists, mystics and metaphysicians he professed to despise. In this, the book is a study in the limitations of the sunny Enlightenment rationalism, at least as it was embodied in the life of one especially gifted and congenitally optimistic Virginian.

This may seem further evidence of authorial presumption. Any attempt to test such a hypothesis should surely get lost in abstraction itself, were it not for the wealth of gritty reality to be mined from the Jefferson archives.

Even so, one yearns for still more revealing detail.

Imagine my excitement, then, to receive an email in the winter of 2003 from the University Virginia graduate student I hired as a researcher. A couple of boxes—perhaps a trunk—of hitherto unexamined Jefferson-related materials had arrived at Alderman Library, and she had received special permission to examine them. There were folders of old letters, memos, songbooks, and even photographs.

Who knew what these sources might reveal?

Alas, not much.

There was no reply to Dr. Watkins’ question. There was no scrawled death threat from Aaron Burr, no hitherto unknown proposal for the abolition of slavery, no late-life conversion to Calvinism, no love letters to Sally Hemings.

Unless, of course, my archivist has been holding out on me.

Perhaps her book will come out someday, blowing all our minds.