Sentence:  Yet oh! what an immense difference did I feel between this impression of a pleasure merely animal, and struck out of the collision of the sexes by a passive bodily effect, from that sweet fury, that rage of active delight which crowns the enjoyments of a mutual love-passion, where two hearts, tenderly and truly united, club to exalt the joy, and give it a spirit and soul that bids defiance to that end which mere <WSD>momentary</WSD> desires generally terminate in, when they die of a surfeit of satisfaction! 
Meaning of the word marked with <WSD> tags:  Ephemeral or relatively short-lived.