Ann Parker here, every other Thursday bloggin' at the LadyKillers. When it comes to dialogue, I count myself lucky among historical writers in that my venue is late nineteenth century United States. (Priscilla, who writes books set in the medieval timeframe, has a much harder row to hoe...)
I can pick up tips on the language and slang of the day as well as the cadence of the spoken word in all sorts of places for my fictional endeavors. As I scan newspaper articles and books written in my particular era of interest (late 1870s to early 1880s), I sometimes feel like a language-obsessed magpie, always looking for that shiny word or "just right" turn of phrase to collect and hoard away.
For instance, here's a short page from New Colorado and the Santa Fe Trail by A. A. Hayes, copyright 1880. (I captured this image from Google books, but I also have a hardcopy, which is a joy to hold in my hands. More about that topic over here.) You can click on the image itself for a closer look at both text and picture.
The cool thing about this excerpt (along with the etching) is the verbal back and forth between a couple of folks riding in a stagecoach heading from Denver "over the Divide."
You have a proper clergyman from back East—who indeed speaks very properly—and a fellow traveler with the appearance of a "road agent" (what a great term, yes?)—who is a lot looser with his commentary and free-er with the slang.
Look at this lovely bit of dialogue between them, beginning with the fierce-looking fellow:
"Stranger, do you irrigate?"
"If you mean drink, sir, I do not."
"Do you object, stranger, to our irrigating?"
"No, sir." And they drank accordingly.
After a farther distance had been traversed, the supposed brigand again asked, "Stranger, do you fumigate?"
"If you mean smoke, sir, I do not."
"Do you object, stranger, to our fumigating?"
"No, sir." And they proceeded to smoke.
Irrigate and fumigate ... there they are, along with definitions nicely supplied, in dialogue from a book with a copyright of 1880.
Think I'm going to squirrel those words away, until the time is right to use them in one of my stories, perhaps in book #5 of the Silver Rush series?
You bet! (See next to last line...)