Discovering Sherlock Holmes - A Community Reading Project From Stanford University

I am certainly developing the wisdom of the serpent….
Watson feels that he is developing wisdom mixed with guile, characteristic of the serpent in folklore.

...and he and the baronet played écarté afterwards.
Écarté is a two-person card game that resembles euchre. It was much in vogue in England and France during the early 19^th century. Perhaps they are a bit behind the times in Dartmoor.

...a lady, who was sitting before a Remington typewriter....
E. Remington & Sons, a firearms company, took up the manufacture of typewriters in 1816. In 1886, the typewriter component of the company was sold, becoming the Remington Typewriter Company. The original manufacturer continues to make firearms to this day.

...the dainty pink which lurks at the heart of the sulphur rose.
Native to South America, the "sulphur rose" is the ancestor of modern yellow roses.

There was something subtly wrong with the face, some coarseness of expression, some hardness, perhaps, of eye, some looseness of lip which marred its perfect beauty.
Conan Doyle skillfully chooses adjectives to describe the lady's face--"coarseness," "hardness," "looseness"--that contain a subtly negative judgment of her moral character.

I knew already that Sir Charles Baskerville had made Stapleton his almoner upon several occasions....
Sir Charles had asked Stapleton to distribute alms, or charity, to local people as his agent.

"My life has been one incessant persecution from a husband whom I abhor. The law is upon his side, and every day I am faced by the possibility that he may force me to live with him."
Divorce laws in England specified the few conditions under which a woman could obtain a divorce. Without proof of extreme cruelty, a woman had little chance of being allowed to separate from her husband. Conan Doyle was a strong advocate for liberalization of these laws.

...and many hundreds of them are scattered throughout the length and breadth of the moor.
In fact, relatively few of the remaining moor huts are complete enough to serve as habitation or hiding place. Most are either ruined or reduced to mere circles, since the thatch and wood that made up their roofs, and all or part of their walls, disintegrated millennia ago.

"I have established a right of way through the centre of old Middleton's park, slap across it, sir, within a hundred yards of his own front door. What do you think of that? We'll teach these magnates that they cannot ride rough-shod over the rights of the commoners, confound them! And I've closed the wood where the Fernworthy folk used to picnic. These infernal people seem to think that there are no rights of property, and that they can swarm where they like with their papers and their bottles."
On the same day, Frankland succeeded in having two contradictory judgments passed: one that exalted the rights of the commoner over the larger landholder, and another that reaffirmed the right of private property. No wonder that he is often burned in effigy by disgruntled townsfolk.