The Big Business Man looked around the room. "There's a few flies around here if we can catch one," he suggested. "I'll bet there's a cockroach in the kitchen," said the Very Young Man, jumping up. The Doctor took a brass check from his pocket. "I thought probably you'd want to try them out. Will you get that box from the check-room?" He handed the check to the Very Young Man, who hurried out of the room. He returned in a moment, gingerly carrying a cardboard box with holes perforated in the top. The Doctor took the box and lifted the lid carefully. Inside, the box was partitioned into two compartments. In one compartment were three little lizards about four inches long; in the other were two brown sparrows. The Doctor took out one of the sparrows and replaced the cover. "Fine," said the Very Young Man with enthusiasm. The Doctor reached for the boxes of chemicals. "Not the big one," said the Banker again, apprehensively. "Hold him, will you," the Doctor said. The Very Young Man took the sparrow in his hands. "Now," continued the Doctor, "what we need is a plate and a little water." "There's a tray," said the Very Young Man, pointing with his hands holding the sparrow. The Doctor took a spoon from the tray and put a little water in it. Then he took one of the tiny pellets from a red vial and crushing it in his fingers, sprinkled a few grains into that water. "Hold that a moment, please." The Big Business Man took the proffered spoon. Then the Doctor produced from his pocket a magnifying glass and a tiny pair of silver callipers such as are used by jewelers for handling small objects. "What's the idea?" the Very Young Man wanted to know. "I thought I'd try and put him on the ring," explained the Doctor. "Now, then hold open his beak." The Very Young Man did so, and the Doctor poured the water down the bird's throat. Most of it spilled; the sparrow twisted its head violently, but evidently some of the liquid had gone down the bird's throat. Silence followed, broken after a moment by the scared voice of the Very Young Man. "He's getting smaller, I can feel him. He's getting smaller." "Hold on to him," cautioned the Doctor. "Bring him over here." They went over to the table by the ring, the Banker and the Big Business Man standing close beside them. "Suppose he tries to fly when we let go of him," suggested the Very Young Man almost in a whisper. "He'll probably be too confused," answered the Doctor. "Have you got him?" The sparrow was hardly bigger than a large horse-fly now, and the Very Young Man was holding it between his thumb and forefinger. "Better give him to me," said the Doctor. "Set him down." "He might fly away," remonstrated the Very Young Man. "No, he won't." The Very Young Man put the sparrow on the handkerchief beside the ring and the Doctor immediately picked it up with the callipers. "Don't squeeze him," cautioned the Very Young Man.