Latin Igne Natura Renovatur Integra ("by fire, nature renews itself");
sources have Igne Natura Renovando Integrat Latin Igne Nitrum Roris Invenitur ("the nitre of dew is found by fire")
Hebrew ימים, נור, רוח, יבשת (Yammīm, Nūr, Rūaḥ, Yabešet, "water, fire, wind, earth" — the four elements)
Iesus Nazarenus, Rex Iudæorum Jesus of Nazareth, the King of the Jews
I.N.R.I: By fire, nature is perfectly renewed
Jesus Nazarenus Rex Judaeorum - Jesus of Nazareth, King of the Jews.
Igne Natura Rerun vatur Integra - By fire, nature is perfectly renewed.
The initials of the Latin sentence which was placed upon the cross: Jesus Nazarenus Rex Judaeorum, meaning Jesus of Nazareth, King of the Jews. The Rosicrucians used them as the initials of one of their Hermetic secrets: 'Igne Natura Rerun vatur Integra,' meaning that By fire, nature is perfectly renewed. They also adopted them to express the names of their three elementary principles salt, sulphur, and mercury by making them the initials of the sentence, Igne Nitrum Roris Invenitur. This corresponds with the Hebrew equivalent letters and initials of the ancient elements: Iaminim, water; Nour, fire; Ruach, air; and Iebschah, earth."
- Albert Mackey, The Encyclopedia of Freemasonry
"This is the philosophical fire, namely of purification. This art is most excellent, if one is learned and diligent; for it possesses both theory and experience. Theory gives understanding, practice gives success, and manual operation follows. Whatever has gone beyond moderation in this art, we shall avoid."