Complex sentence: The particular narcotic used by the lines of Reverend Mothers on Arrakis is the Water of Life, the liquid exhalation of a sandworm produced at the moment of its death by drowning.
Split into simpler sentences: The particular narcotic used by the lines of Reverend Mothers on Arrakis is the Water of Life. The liquid exhalation of a sandworm produced at the moment of its death by drowning.