The Re-echo Club: as by Henry Wadsworth Longfellow (Purple Cow)

The day is done, and the darkness
Falls from the wing of night
As ballast is wafted downward
From an air-ship in its flight.

I dream of a purple creature
Which is not as kine are now;
And resembles cattle only
As Cowper resembles a cow.

Such cows have power to quiet
Our restless thoughts and rude;
They come like the Benedictine
That follows after food.