When Joseph Conrad’s Nostromo was first published in 1904, many of the words used in the text must have been unfamiliar to the general public.
The common folk of the neighborhood, peons of the estancias, vaqueros of the seaboard plains, tame Indians coming miles to market with a bundle of sugar-cane or a basket of maize worth about three-pence, are well aware that heaps of shining gold lie in the gloom of the deep precipices cleaving the stony levels of Azuera. Tradition has it that many adventurers of olden time had perished in the search. The story goes also that within men’s memory two wandering sailors–Americanos, perhaps, but gringos of some sort for certain–talked over a gambling, good-for-nothing mozo, and the three stole a donkey to carry for them a bundle of dry sticks, a water-skin, and provisions enough to last a few days. Thus accompanied, and with revolvers at their belts, they had started to chop their way with machetes through the thorny scrub on the neck of the peninsula.
Patrick O’Brien’s historic novels are full of period flourish, old slang and social commentary, not to mention the nautical jargon, that makes the text often difficult to decipher.
It is clear you have been a great while at sea, to call those sandy-haired coarse-featured pimply short-necked thick-fingered vulgar-minded lubricious blockheads by such a name. Nymphs, forsooth. If they were nymphs, they must have had their being in a tolerably rank and stagnant pool; the wench on my left had an ill breath, and turning for relief I found her sister had a worse; and the upper garment of neither was free from reproach. Worse lay below, I make no doubt. “La, sister,” cries the one to the other, breathing across me — vile teeth; and “La, sister,” cries the other. I have no notion of two sisters wearing the same clothes, the same flaunting meretricious gawds, the same tortured Gorgon curls low over their brutish criminal foreheads; it bespeaks a superfetation of vulgarity, both innate and studiously acquired. And when I think that their teeming loins will people the East. . . . Pray pour me another cup of coffee. Confident brutes.
And then there is Anthony Burgess and his Nadsat.
Our pockets were full of deng, so there was no real need from the point of view of crasting any more pretty polly to tolchock some old veck in an alley and viddy him swim in his blood while we counted the takings and divided by four, nor to do the ultra-violent on some shivering starry grey-haired ptitsa in a shop and go smecking off with the till’s guts. But, as they say, money isn’t everything.
Obscure and unfamiliar words make for good atmosphere. Also, new vocabulary is sometimes necessary when elaborate world building is involved. A creature on an alien planet or a mythical world is not likely to cry out “Oh, Jesus!”. Think of all the invented concepts in The Lord of the Rings.
But how much strange words make good atmosphere and how much is too much? A Clockwork Orange was well received by critics but barely sold at all until it was adapted into a movie. Burgess claimed that the novel was “knocked off for money in three weeks” which would be an impressive feat if true. Yet, if it was written for money, there is little sign of it.
By contrast, Patrick O’Brien’s Aubrey–Maturin series sold over 2 million copies by the time of O’Brien’s death in spite of the period English and nautical terms. I am a sailor more familiar with deadeyes and belaying pins than kevlar sails and satnav but even I have trouble picturing how the top’s’l was woolded to the mizzen. Readers lapped it up as ingredients to the atmosphere.
The reader does not have to understand every word in a book. At least not immediately. But there is a limit to it. The limit varies depending the type of story, but the limit is there. Good luck trying to figure it out though.
(I like to sneak in a few Japanese words here and there, but I like it more when I discover other writers doing it. I was reading the biography of George Crile (1864-1943) and found Crile describing the opposition he faced when he tried to introduce blood pressure monitoring to surgery as “the grey haired shoguns of the medical establishment”. He wrote that sometime in the 1930’s.)