inchangeability

Noun

 * 1)  unchangeableness
 * 2) * 1784, William Kenrick, A Rhetorical Grammar of the English Language (section 6, page 47)
 * Almost all our English writers on this subject, possessed with this inchangeability of accent and quantity, tell us, that all accented syllables are long, making at the same time no distinction between the grave and acute accent.
 * 1) * 23 November 1850,, letter to Julius Plücker
 * I hope one day to return to the subject of magnetic or diamagnetic bodies and their inchangeability or their convertibility.