The spelling of the word "spirit of Mindererus" is a subject of debate among scholars. The word refers to a solution of ammonium acetate used in medicine. The IPA phonetic transcription of the word is /ˈspiːrɪt ʌv maɪnˈdɛrəs/. The spelling of "Mindererus" is derived from the name of its discoverer, a German physician named Johann Joachim Becher, who used the Latinized form "Mindererus." However, some sources use "Mindereus," "Minderer," or "Myn der Eer." Regardless of the spelling, the "spirit of Mindererus" is still used in the medical field today.
Liquor ammonii acetatis.
A practical medical dictionary. By Stedman, Thomas Lathrop. Published 1920.