Name That Tune

The following is excerpted from a classic work of literature.  My challenge: can you identify the book in question?  It's one I believe many of my readers have read.  It was written in the last 150 years, in English, and continues to be read to this day.  I've removed all proper names, so as not to give it all away.

By the way, in case it's not clear: the passage opens with someone speaking.

`And you, you will come too, young brother; for the days pass, and never return, and the South still waits for you. Take the Adventure, heed the call, now ere the irrevocable moment passes!' 'Tis but a banging of the door behind you, a blithesome step forward, and you are out of the old life and into the new! Then some day, some day long hence, jog home here if you will, when the cup has been drained and the play has been played, and sit down by your quiet river with a store of goodly memories for company. You can easily overtake me on the road, for you are young, and I am ageing and go softly. I will linger, and look back; and at last I will surely see you coming, eager and light- hearted, with all the South in your face!'

The voice died away and ceased as an insect's tiny trumpet dwindles swiftly into silence; and _____, paralysed and staring, saw at last but a distant speck on the white surface of the road.

Mechanically he rose and proceeded to repack the luncheon-basket, carefully and without haste. Mechanically he returned home, gathered together a few small necessaries and special treasures he was fond of, and put them in a satchel; acting with slow deliberation, moving about the room like a sleep-walker; listening ever with parted lips. He swung the satchel over his shoulder, carefully selected a stout stick for his wayfaring, and with no haste, but with no hesitation at all, he stepped across the threshold just as ____ appeared at the door.

`Why, where are you off to, ___?' asked ___ in great surprise, grasping him by the arm.

`Going South, with the rest of them,' murmured ___ in a dreamy monotone, never looking at him. `Seawards first and then on shipboard, and so to the shores that are calling me!'

He pressed resolutely forward, still without haste, but with dogged fixity of purpose; but ___, now thoroughly alarmed, placed himself in front of him, and looking into his eyes saw that they were glazed and set and turned a streaked and shifting grey--not his friend's eyes, but the eyes of some other animal! Grappling with him strongly he dragged him inside, threw him down, and held him.

___ struggled desperately for a few moments, and then his strength seemed suddenly to leave him, and he lay still and exhausted, with closed eyes, trembling. Presently ___ assisted him to rise and placed him in a chair, where he sat collapsed and shrunken into himself, his body shaken by a violent shivering, passing in time into an hysterical fit of dry sobbing.