"That's so," said the Banker, looking relieved. "I never thought of that."

"One of us should stay at least," said the Doctor. "We cannot take any outsider into our confidence. One of us must watch the others go, and then take the ring back to its place in the Museum. We will be gone too long a time for one person to watch it here."

The Very Young Man suddenly went to one of the doors and locked it.

"We don't want any one coming in," he explained as he crossed the room and locked the others.

"And another thing," he went on, coming back to the table. "When I saw the ring at the Biological Society the other day, I happened to think, suppose Rogers was to come out on the underneath side? It was lying flat, you know, just as it is now." He pointed to where the ring lay on the handkerchief before them. "I meant to speak to you about it," he added.

"I thought of that," said the Doctor. "When I had that case built to bring the ring here, you notice I raised it above the bottom a little, holding it suspended in that wire frame."

"We'd better fix up something like that at the Museum, too," said the Very Young Man, and went back to his walk.

The Big Business Man had been busily jotting down figures on the back of an envelope. "I can be in shape to go in three weeks," he said suddenly.

"Bully for you," said the Very Young Man. "Then it's all settled." The Big Business Man went back to his notes.

"I knew what your answer would be," said the Doctor. "My patients can go to the devil. This is too big a thing."

The Very Young Man picked up one of the tin boxes. "Tell us how you made the powders," he suggested.

The Doctor took the two boxes and opened them. Inside each were a number of tiny gla.s.s vials. Those in one box were of blue gla.s.s; those in the other were red.

"These vials," said the Doctor, "contain tiny pellets of the completed drug. That for diminishing size I have put in the red vials; those of blue are the other drug.

"I had rather a difficult time making them--that is, compared to what I antic.i.p.ated. Most of the chemicals I bought without difficulty. But when I came to compound those two myself"--the Doctor smiled--"I used to think I was a fair chemist in my student days. But now--well, at least I got the results, but only because I have been working almost night and day for the past month. And I found myself with a remarkably complete experimental laboratory when I finished," he added. "That was yesterday; I spent nearly all last night destroying the apparatus, as soon as I found that the drugs had been properly made."

"They do work?" said the Very Young Man anxiously.

"They work," answered the Doctor. "I tried them both very carefully."

"On yourself?" said the Big Business Man.

"No, I didn't think that necessary. I used several insects."

"Let's try them now," suggested the Very Young Man eagerly.

"Not the big one," said the Banker. "Once was enough for that."

"All right," the Doctor laughed. "We'll try the other if you like."

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 c.o.c.kroach in the kitchen," said the Very Young Man, jumping up.

The Doctor took a bra.s.s 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 part.i.tioned 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 gla.s.s 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.

The sparrow grew steadily smaller, and in a moment the Doctor set it carefully on the rim of the ring.

"Get him up by the scratch," whispered the Very Young Man.

The men bent closer over the table, as the Doctor looking through his magnifying gla.s.s shoved the sparrow slowly along the top of the ring.

"I can't see him," said the Banker.