"Star Bright", a novelette by Jack Williamson, first published in Argosy, November 25, 1939.
There is a man who discovers that he can make things simply by thinking them.
He touched his bleeding forehead, and hoped the wound would heal safely. When he tried to rise, a faintness seized him. A sudden thirst parched his throat.
"Water!" he breathed.
As he sank giddily back on his elbow, that thirst set in his mind the image of a sparkling glass of water. It sat on a flat rock, glittering in the moonlight. It looked so substantial that he reached out and picked it up.
Without surprise, he drank. A few swallows relieved his thirst, and his mind cleared again. Then the sudden realization of the incredible set him to quivering with reasonless panic.
The glass dropped out of his fingers, and shattered on the rock. The fragments glittered mockingly under the moon. Mr. Peabody blinked at them.
"It was real!" he whispered. "I made it real—out of nothing. A miracle—I worked a miracle!"
So he tries gold bricks.
There couldn't be any crime about making real gold. But the project proved more difficult than Mr. Peabody had expected. The first dim outlines of the brick began to waver, and he felt sick and dizzy.
The steady beat of pain filled all his head, stronger than it had ever been. The rush of unseen power became a mighty hurricane, blowing away his consciousness. Desperately, he clutched at the back of a chair.
The massive yellow ingot at last shimmered real, under the lamp. Mopping weakly at the sweat on his face, Mr. Peabody made a gesture of weary triumph and sat down.
But when he inspects said brick he finds it is lead because he doesn't understand the root of the thing.
"Dad, you aren't—insane?"
Mr. Peabody felt a tremor of ungovernable apprehension.
"Of course not, daughter. Why?"
"Mother and Bill have been telling me the most horrid things," she whispered, staring at him. "They said you were playing with dead flies and a cockroach, and saying you could work miracles, and giving them counterfeit money and stolen jewelry and a fake gold brick—"
"Fake?" He gulped. "No; it was real gold."
Beth shook her troubled head.
"Bill showed me," she whispered. "It looks like gold on the outside. But when you scratch it, it's only lead."
So he learns about molecules and all sorts of things, and eventually makes a real gold brick.
After the doctor had given him a lesson on the latest discoveries about atomic and molecular structures, he found himself able to create objects of the precious metals, with none of them turning out like the gold brick.
For two days he drove himself to exhaustion, making gold and platinum. He shaped the metal into watch cases, old-fashioned jewelry, dental work, and medals, so that it could be disposed of without arousing suspicion.
Brant took a handful of the trinkets to a dealer in old gold. He returned with five hundred dollars, and the assurance that the entire lot, gradually marketed, would net several thousand.
Then he moves to animals, makes a goldfish, but it is dead because he doesn't get it. So he learns about the anatomy, eventually makes animals.
And presently, with a manual of marine biology on his knees, Mr. Peabody was forming small miraculous goldfish in the bowl he had made on the night of his arrival. They were gleaming, perfect—except that they always floated to the top of the water, dead.
Then he moves to humans, and as he is learning to make an arm, a foot, a leg,
The doctor evidently had grandiose ideas of a miraculous human being. He set Mr. Peabody to studying and creating human limbs and organs. After a few days, the bathtub was filled with a strange lot of miraculous debris, swimming in a preservative solution.
he gets arrested because he has a bathub full of body parts.
"Hey, Sergeant!" came an excited shout from the bathroom. "Looks like Doc Brant is in the ring, too. And it ain't only jewel-robbery and counterfeiting. It's murder—with mutilation!"