The nerves conduct the animal spirits to act upon the muscles, and in their turn convey the impressions of the organs to the brain.
As in the Directions, the satire, though cutting, is good-natured, and the piece shows more animal spirits than usual in Swift's latter years.
On one hand the animal spirits " reflected " 2 from the image formed on the pineal gland proceed through the nervous tubes to make the muscles turn the back and lift the feet, so as to escape the cause of the terror.
Such an exuberance of animal spirits had he that he sometimes tumbled down and rolled on the ground with laughter at anything which made him think and tickled him.