"Gentlemen," said the doctor in ringing tones, "allow me to present to you Professor James Kirkwood of the faculty of the Richton University, formerly known as James Collier of the Bureau of Standards, and robber of the First National Bank."

Detective-Captain Sturtevant jumped to his feet and cast a searching glance at the captive.

"He's the man all right," he cried. "Hang on to him until I get a wagon here!"

"Oh, shut up!" said Carnes. "He's under federal arrest just now, charged with the possession of narcotics. When we are through with him, you can have him if you want him."

"How did you get that picture, Doctor?" cried the cashier. "I watched that cage every minute during the morning and I'll swear that man never entered and stole that money as the picture shows, unless he managed to make himself invisible."

"You're closer to the truth than you suspect, Mr. Rogers," said Dr.

Bird. "It is not quite a matter of invisibility, but something pretty close to it. It is a matter of catalysts."

"What kind of cats?" asked the cashier.

"Not cats, Mr. Rogers, catalysts. Catalysts is the name of a chemical reaction consisting essentially of a decomposition and a new combination effected by means of a catalyst which acts on the compound bodies in question, but which goes through the reaction itself unchanged. There are a great many of them which are used in the arts and in manufacturing, and while their action is not always clearly understood, the results are well known and can be banked on.

"One of the commonest instances of the use of a catalyst is the use of sponge platinum in the manufacture of sulphuric acid. I will not burden you with the details of the 'contact' process, as it is known, but the combination is effected by means of finely divided platinum which is neither changed, consumed or wasted during the process. While there are a number of other catalysts known, for instance iron in reactions in which metallic magnesium is concerned, the commonest are the metals of the platinum group.

"Less is known of the action of catalysts in the organic reactions, but it has been the subject of intensive study by Dr. Knolles of the Bureau of Standards for several years. His studies of the effects of different colored lights, that is, rays of different wave-lengths, on the reactions which const.i.tute growth in plants have had a great effect on hothouse forcing of plants and promise to revolutionize the truck gardening industry. He has speeded up the rate of growth to as high as ten times the normal rate in some cases.

"A few years ago, he and his a.s.sistant, James Collier, turned their attention toward discovering a catalyst which would do for the metabolic reactions in animal life what his light rays did for plants. What his method was, I will not disclose for obvious reasons, but suffice it to say that he met with great success. He took a puppy and by treating it with his catalytic drugs, made it grow to maturity, pa.s.s through its entire normal life span, and die of old age in six months."

"That is very interesting, Doctor, but I fail to see what bearing it has on the robbery."

"Mr. Rogers, how, on a dark day and in the absence of a timepiece, would you judge the pa.s.sage of time?"

"Why, by my stomach, I guess."

"Exactly. By your metabolic rate. You eat a meal, it digests, you expend the energy which you have taken into your system, your stomach becomes empty and your system demands more energy. You are hungry and you judge that some five or six hours must have pa.s.sed since you last ate. Do you follow?"

"Certainly."

"Let us suppose that by means of some tonic, some catalytic drug, your rate of metabolism and also your rate of expenditure of energy has been increased six fold. You would eat a meal and in one hour you would be hungry again. Having no timepiece, and a.s.suming that you were in a light-proof room, you would judge that some five hours had pa.s.sed, would you not?"

"I expect so."

"Very well. Now suppose that this accelerated rate of digestion and expenditure of energy continued. You would be sleepy in perhaps three hours, would sleep about an hour and a quarter, and would then wake, ready for your breakfast. In other words, you would have lived through a day in four hours."

"What advantage would there be in that?"

"None, from your standpoint. It would, however, increase the rate of reproduction of cattle greatly and might be a great boom to agriculture, but we will not discuss this phase now. Suppose it were possible to increase your rate of metabolism and expenditure of energy, in other words, your rate of living, not six times, but thirty thousand times. In such a case you would live five minutes in one one-hundredth of a second."

"Naturally, and you would live a year in about seventeen and one-half minutes, and a normal lifespan of seventy years in about twenty hours.

You would be as badly off as any common may-fly."

"Agreed, but suppose that you could so regulate the dose of your catalyst that its effect would last for only one one-hundredth of a second. During that short period of time, you would be able to do the work that would ordinarily take you five minutes. In other words, you could enter a bank, pack a satchel with currency and walk out. You would be working in a leisurely manner, yet your actions would have been so quick that no human eye could have detected them. This is my theory of what actually took place. For verification, I will turn to Dr. Kirkwood, as he prefers to be known now."

"I don't know how you got that picture, but what you have said is about right," replied the prisoner.

"I got that picture by using a speed of thirty thousand times the normal sixteen exposures per second," replied Dr. Bird. "That figure I got from Dr. Knolles, the man who perfected the secret you stole when you left the Bureau three years ago. You secured only part of it and I suppose it took all your time since to perfect and complete it. You gave yourself away when you experimented on young Ladd. I was a track man myself in my college days and when I saw an account of his running, I smelt a rat, so I came back and watched him. As soon as I saw him crush and swallow a capsule just as the gun was fired, I was sure, and got hold of him. He was pretty stubborn, but he finally told me what name you were running under now, and the rest was easy. I would have got you in time anyway, but your bravado in telling us when you would next operate gave me the idea of letting you do it and photographing you at work. That is all I have to say. Captain Sturtevant, you can take your prisoner whenever you want him."

"I reckoned without you, Dr. Bird, but the end hasn't come yet. You may send me up for a few years, but you'll never find that money. I'm sure of that."

"Tut, tut, Professor," laughed Carnes. "Your safety deposit box in the Commercial National is already sealed until a court orders it opened.

The bills you took this morning were all marked, so that is merely additional proof, if we needed it. You surely didn't think that such a transparent device as changing your name from 'James Collier' to 'John Collyer' and signing with your left hand instead of your right would fool the secret service, did you? Remember, your old Bureau records showed you to be ambidextrous."

"What about Winston's confession?" asked Rogers suddenly.

"Detective-Captain Sturtevant can explain that to a court when Mr.

Winston brings suit against him for false arrest and brutal treatment,"

replied Carnes.

"A very interesting case, Carnes," remarked the doctor a few hours later. "It was an enjoyable interlude in the routine of most of the cases on which you consult me, but our play time is over. We'll have to get after that counterfeiting case to-morrow."

IN THE NEXT ISSUE

BRIGANDS OF THE MOON _Beginning an Amazing Four-part Interplanetary Novel_ By RAY c.u.mMINGS

THE SOUL MASTER _A Thrilling Novelette of the Subst.i.tution of Personality_ By WILL SMITH and R. J. ROBBINS

COLD LIGHT _An Extraordinary Scientific Mystery_ By CAPT. S. P. MEEK

--_AND MANY OTHER STORIES, OF COURSE_

[Ill.u.s.tration: "_She is Yours, Master!_"]

Sick at heart, the trembling girl shuddered at the words that delivered her to this terrible fate of the East. How could she escape from this Oriental monster into whose hands she had been given--this mysterious man of mighty power whose face none had yet seen?

Here is an _extraordinary situation_. What was to be the fate of this beautiful girl? Who was this strange emissary whom no one really knew?

_To know the answer to this and the most exciting tales of Oriental adventure and mystery ever told, read on through the most thrilling, absorbing, entertaining and fascinating pages ever written._

Masterpieces of Oriental Mystery 11 Superb Volumes by SAX ROHMER Written with his uncanny knowledge of things Oriental