Quickening

I can feel my pulse quickening already.

Source: tatoeba (3729739)

Books are the bees which carry the quickening pollen from one to another mind.

Source: tatoeba (6086685)

He writes his history upon his field; how many ties, how many resources, he has,—his friendships with his cattle, his team, his dog, his trees, the satisfaction in his growing crops, in his improved fields; his intimacy with nature, with bird and beast, and with the quickening elemental forces; his cooperations with the clouds, the sun, the seasons, heat, wind, rain, frost!

Source: tatoeba (11764922)

If the following guide lose his distance from the one leading (which can only happen by his own fault), he will correct himself by slightly lengthening or shortening a few steps, in order that there may not be sudden quickenings or slackenings in the march of his platoon.

Source: wiktionary