Here’s a phrase you don’t read much nowadays: brown study. First cited in the sixteenth century (specifically in a book called Dice-Play), the expression—which describes a state of intense, sometimes melancholy reverie—really seems to have hit its stride in the nineteenth. Dr. Watson describes “falling into a brown study” in the course of “The Adventure of the Cardboard Box.” In Louisa May Alcott’s Eight Cousins, Uncle Alec “paced up and down the lower hall in the twilight for an hour, thinking so intently that sometimes he frowned, sometimes he smiled, and more than once he stood still in a brown study.” In David Copperfield, Dickens uses it like this: “I fell into a brown study as I walked on, and a voice at my side made me start.” Meanwhile, here’s Conrad, in “Thrift and the Child”:

He ceased and sat solemnly dejected, in a brown study. What day? I asked at last; but he did not hear me apparently. He suffused such portentous gloom into the atmosphere that I lost patience with him.

These were all books written for a popular audience; presumably the phrase was in regular use in both the English and American vernacular. What seems puzzling now would not have to a population who knew brown as a color associated with sadness. Indeed, brown was once used the way we do blue today—to connote melancholy. And it’s a good phrase, well suited to stories sustained by brisk narrative pace; in such cases as these, it was doubtless useful to be able to sketch interiority in a couple of words.

However, there are brown studies and brown studies. In an 1867 volume of The Saturday Review of Politics, Literature, Science and Art, a critic took George Sand to task thus: “Whether it be that the veteran novelist has for once overstrained her powers by a forced and unnatural effort, or that a brown study is a mental attitude wholly foreign to the temperament of Madame Sand, La Reverie a Paris strikes us as about the dullest and most vapid piece of writing in the book.”

After that, I had to read this abomination—and while it didn’t set the world on fire, I thought the reviewer was a bit harsh. In any event, if this is how private musings were greeted, you can see why a writer of the period might have felt more comfortable sticking to a two-word abstraction—however vague.