What language specifically did Nostradamus use to write his original prophecies?

That would be French: Nostradamus - Wikipedia, the free encyclopedia

Nostradamus was French and he spoke and wrote largely in French. His famous quatrains of supposed prophecies were written in a mixture of French, Greek, Italian, Latin and Provencal and using a “Virgilianized” syntax. (Yahoo)

"Nostradamus lived and wrote during a period of political and religious censorship. Because of this it is said he disguised his writings not only with somewhat cryptic language, but in four different languages (Latin, French, Italian and Greek). Not content with such obfuscation, Nostradamus is also said to have used anagrams to further confuse potential inquisitors (particularly with respect to names and places)." (Wikipedia)

Thanks for the Info.