Prunes and prisms refer to a quote by the prim and snobby Mrs. General, in Charles Dickens’ novel Little Dorrit. When the Dorrit girls and their family are released from the Marshalsea Prison, Mr. Dorrit undertakes to hire a companion for his daughters that will help give them “polish” and finish. Mrs. General becomes this companion, and is always imparting annoying words of advice, which the daughters feel free to ignore.
The direct quote often associated with the terms is the following: “Papa, potatoes, poultry, prunes and prism are all very good words for the lips.” Dickens further goes on to detail several chapters on the nature of prunes and prisms and how the Dorrit girls are oppressed by the snobbery and prim nature of Mrs. General.
Dickens' specific choice of words are interesting. Papa, potatoes, poultry and prunes are all mundane words, and will certainly result in the pursed lip shape of the mouth suggested as the best way to appear by Mrs. General. However, the word prism requires a bit more analysis.
A prism is often associated with reflecting light, or a source through which light passes in order to make rainbows. It could be read as a suggestion that the polite lady, according to Mrs. General, should be one who is transparent, mundane, and who allows others around her to shine. The proper woman is not the source of her own light, but rather merely ornamental, reflecting the opinions of others rather than advancing her own. This is much in keeping with the concept of the Victorian woman being the ornamental “Angel of the House.”
In any case, Dickens clearly hit the mark with prunes and prisms, with continued references to it as a state of being in other works of literature. For example, Louisa May Alcott refers to prunes and prisms in Little Women and at least one other novel. Lucy Maud Montgomery sneaks the concept this sort of mouth into several of her Anne of Green Gables books. The term becomes metaphoric for disapproval, lack of humor, and snootiness, just as the pursed lips that Mrs. General advocates for suggest an air of displeasure.
Though Oscar Wilde was not a huge Dickens fan, prunes and prisms clearly influence his character of Ms. Prism in The Importance of Being Earnest. Ms. Prism is yet another governess with high-toned morals, snobbery, and prudishness. Many see her as a direct echo of Mrs. General, though at the end of the play, she is revealed to have led less than a perfect life.
Reference to prunes and prisms continue into the mid 20th century. A 1937 article in Time Magazine about Virginia Woolf refers to her as not having had that type of education. C.S. Lewis’ second Narnia novel, Prince Caspian, originally published in 1951, has a character named Queen Prunaprismia.
As Dickens’ less well-known novels are read with less frequency, references to prunes and prisms declined in the late 20th century.