A little about the authoress…
Georgiana Spencer (1757-1806) was born into one of the wealthiest families of England, which came with the expectation that she’d one day marry rich and well. She fulfilled this duty in 1774 when she married William Cavendish, 5th Duke of Devonshire (1748-1811). Their union would be an unhappy one, but Georgiana’s standing in society gave her an outlet for her charisma, which she would channel into being a socialite, fashion icon, author, and political activist.
Georgiana, affectionately called Gee, set fashion trends, such as three-foot ostrich feather headdresses. She valued the ideals of the Enlightenment, which drove her political advocacy for the Whig Party. She organized multitudes of women, in a time when women could not vote, to campaign for the Whigs.
She also wrote a book called The Sylph and published it anonymously in 1778, which depicted several of her contemporaries as libertines, blackguards, gamblers, and alcoholics. She maintained a small laboratory where she experimented with chemistry. Horace Walpole (1717-1797), author of The Castle of Otranto, even sang her praises, calling her a “phenomenon.”
However, as alluded to earlier, her life wasn’t always a sparkling one. She suffered from a gambling addiction, which saw her burdened with debts. Her marriage to William Cavendish, as alluded to earlier, was unaffectionate and suffocating. She had an extramarital affair with the future Prime Minister of England (1830-1834), Charles Grey (1764-1845), and had a daughter out of wedlock with him. William forced her to hand the child, named Eliza, over to Charles Grey’s family. William Cavendish, on the other hand, had an affair with one of Georgiana’s friends, Lady Elizabeth Foster (1758-1824), also known as Bess. He moved Bess into Chiswick House, where the three openly lived as a ménage à trois until Georgiana’s death. William married Bess three years after.
Some of Georgiana’s own words have trickled down from the Georgian era to the present. Here are a few quotes from her novel, The Sylph, to which the heroine, Julia Grenville, has many parallels with Georgiana’s life. Many of the characters are also literary portraits of many of her aristocratic contemporaries. Please enjoy, and if you’d like to read The Sylph, it’s available on Project Gutenberg.

“So away goes reflection; and we are whirled away in the stream of dissipation, with the rest of the world. This seems a very sufficient reason for every thing we do, The rest of the world does so: that’s quite enough.” – The Sylph
“Curses, everlasting curses, blast me for my damned love of play! That has been my bane.” – The Sylph
“The most unsafe and critical situation for a woman, is to be young, handsome, and married to a man of fashion; these are thought to be lawful prey to the specious of our sex.” – The Sylph

“So away goes reflection; and we are whirled away in the stream of dissipation, with the rest of the world. This seems a very sufficient reason for every thing we do, The rest of the world does so: that’s quite enough.” – The Sylph
“My native country! exclaimed he, What is my native country, what the whole globe itself, to that spot which contains all?” – The Sylph
“The name of love has awakened a thousand, thousand pangs, which sorrow had hushed to rest; at least, I kept them to myself.” – The Sylph

References
Georgiana Cavendish on Brooklyn Museum
Georgiana Cavendish, Duchess of Devonshire (1757-1806) by Rachel Knowles, Regency History
Georgiana the Scientist on The Duchess of Devonshire’s Gossip Guide to the 18th Century
“passing the love of woman”, Georgiana Cavendish’s relationships with women by Alexandra Burns, Chiswick House & Gardens
‘ROMANTIC FEMALE FRIENDSHIP’: GEORGIANA, DUCHESS OF DEVONSHIRE AND CHISWICK HOUSE on English Heritage
THE SYLPH By GEORGIANA, DUCHESS OF DEVONSHIRE on Project Gutenberg
The Sylph: The Duchess of Devonshire’s pre-Gothic and pre-Romantic Novel by Tyler Tichelaar, Ph.D., The Gothic Wanderer
What can “The Sylph” tell us about its author, Georgiana, Duchess of Devonshire? by Rachel Knowles, Regency History
She certainly packed a lot into what was a fairly short life by today’s standards.
She certainly did!