The Charwoman's Shadow by Lord Dunsany

When the crone had revealed the mean and trivial purpose for which the Master of the Art had cast her helpless upon the ages, she voiced her regrets no more; but, once more warning the young man against the magician's prices, she turned about with her lantern and went shadowless out of the room. Ramon Alonzo had heard and disregarded tales of men that had paid their shadows as the price for certain dealings within the scope of the Art; but he had never before considered the value of shadows. He saw now that to lose his shadow and to come to yearn for it when it were lost, and to lose the little greetings that one daily had from one's kind, and to hear no more tattle about trivial things; to see smiles no more, nor to hear one's name called friendly; but to have the companionship only of shadowless things, such as that old woman, and wandering spirits, and dreams, might well be to pay too much for the making of gold. And, well warned now, he decided that come what may he would never part with his shadow. In his gratitude he determined to ask the magician for some respite for that poor old woman from scrubbing his floors through the ages.

And then his thoughts went back to his main purpose, to what metals were suited best for transmutation, and whether he could turn them into gold himself if the magician's price were too high: other men had done it; why not he? And, led towards absurdity by this delightful hope, his thoughts grew wilder and wilder till they were dreams.