H.G. Wells The Invisible Man (1897)
It seems strange to consider that only a decade separates The Invisible Man from Robert Louis Stevenson's Dr. Jeckyll and Mr. Hyde, both tales wherein the process of scientific investigation unwittingly exposes the darker, amoral side of its investigator. Stevenson's tale is very much the nineteenth century examination of morality with its main guy neatly bifurcated into good and evil just like the Christian and immediately post-Christian universe into which he was born. Wells' Griffin is on the other hand a man transformed rather than divided in Stevenson's sense - a man who, through the agency of science, believes himself beyond consequence and thus goes on a rampage. The Invisible Man is therefore, according to Wikipedia, an update of the Ring of Gyges from Plato's Republic, which I really should have remembered seeing as I only read the fucking thing a month ago, but never mind.
More significantly, The Invisible Man doesn't feel like a nineteenth century novel, and its compelling, amiable tone is perhaps indicative of why Wells is still deservedly regarded as a classic author. He communicates; his science is ingenious yet never overpowers its narrative; his phonetic renderings of regional accents entertain without intruding where so often such a device can come across as painfully twee or even render the narrative incomprehensible - as with certain short stories by the previously mentioned Stevenson; and he is often very funny without conspicuously trying too hard:
Elaborated in the imagination of Mr. Gould, the probationary assistant in the National School, this theory took the form that the stranger was an Anarchist in disguise, preparing explosives, and he resolved to undertake such detective operations as time permitted. These consisted for the most part in looking very hard at the stranger whenever they met, or in asking people who had never seen the stranger leading questions about him.
On close inspection, this is a pretty thin tale and there's not actually a whole lot of story beyond bloke turns invisible, goes bonkers, but the telling is delicious, amounting to a robust meal - if culinary analogies aren't too much of a stretch.