The Witch of Agnesi

THE WITCH OF AGNESI

The title of this post is also the title of my first Bonnie Pinkwater mystery.  I can't even begin to tell you the number of disgruntled e-mails this title has engendered.  A reader recently sent me a message letting me know that he read the first hundred pages and felt cheated when no paranormal activity ensued.  He then proceeded to give me a one star review and promised to read no further.  A move which I think is reasonable. I mean there it is, a title that contains the word witch with no 'Bubble, bubble toil and trouble', no love potions, no green faced crone who melts because a singing girl from a black and white Kansas gave her an impromptu shower, and certainly no seemingly sweet old lady who lived in a gingerbread house with a candy cane chimney, who for cannibalistic purposes fattened up a boy running around the Black Forest wearing those funny pants we see in the Sound of Music. It's amazing this reader didn't ask for my head on a spike.

And now the real reason for this post.  I have been invited to write a series of guest posts about historic mathematicians.  I thought to myself, "Self, if you're going to post this bad boy in someone else's blog, why not post it in your own as well?" Sadly, I do speak to myself in this fashion.

Sooooooo, if you have no interest in a story about a really cool female mathematician this would be a good time to slip quietly away and perhaps go back to reading 'Game of Thrones'.

Marie Gaetana Agenesi, who's name has been lent to this misnomer of a book title, was born in Milan in 1718.  Her father was a professor of Mathematics at the University of Bologna. Brilliant, her early years read much like those of Mozart. By five, she could speak French.  By nine she had mastered Hebrew, Latin, Greek, and most of the languages of Europe.  By her teen years she was well into her formal study of Mathematics: Newton, Leibnitz, Fermat, Descartes, Euler, and the Bernoulli brothers.  By twenty, she had begun her most famous--and we shall later learn her most infamous--mathematical work Analytic Institutions.  In this master work she continued--among other things--the analytic geometry of Fermat, in particular the study of curves. She would also tackle the newly developed areas of Differential and Integral Calculus.

All of this brilliant work would be eclipsed by a bizarre incident that happened two years after Marie's death.  In Analytic Institutions Marie discussed at length a geometric curve called a versed cubic curve.  In Italian she called this curve Versiera, a musical sounding term that means nothing more than 'a curve that turns'. 

Marie would die in 1799 and in 1801 a Cambridge mathematician, John Colson took up the task of translating Marie's wonderful text.  It needs to be said that Professor Colson did an admirable job with his translation.  In fact he translated the entirety of Analytic Institutions perfectly--except for one word.  When Colson translated Versiera he added one letter to the Italian word making it Aversiera.  One might ask how much would the translation be changed by the addition of one insignificant letter?  Well, unfortunately, in this case a great deal. You see while the word Versiera means 'a curve that turns' the word Aversiera means 'Bride of the Devil'.  Thus Marie's innocent geometric curve was renamed 'The Witch of Agnesi.'

While all of this might seems comical to a modern reader; after all we're just talking about an absurd mistake, it is unlikely Marie herself would have agreed.  You see the great ambition of Marie Gaetana Agnesi (one that her father denied her) was to become a nun. Maybe it was a good thing she died before Colson did a number on her reputation.