Part 25 (2/2)

”Now, the alpha rays are the shortest,” he launched forth, ”in length let us say one inch. They exert a very destructive effect on healthy tissue. That is the cause of injury. They are stopped by gla.s.s, aluminum and other metals, and are really particles charged with positive electricity. The beta rays come next, say, about an inch and a half. They stimulate cell growth. Therefore they are dangerous in cancer, though good in other ways. They can be stopped by lead, and are really particles charged with negative electricity. The gamma rays are the longest, perhaps three inches long, and it is these rays which effect cures, for they check the abnormal and stimulate the normal cells. They penetrate lead. Lead seems to filter them out from the other rays. And at three inches the other rays don't reach, anyhow. The gamma rays are not charged with electricity at all, apparently.”

He had brought a little magnet near the spinthariscope. I looked into it.

”A magnet,” he explained, ”shows the difference between the alpha, beta, and gamma rays. You see those weak and wobbly rays that seem to fall to one side? Those are the alpha rays. They have a strong action, though, on tissues and cells. Those falling in the other direction are the beta rays. The gamma rays seem to flow straight.”

”Then it is the alpha rays with which we are concerned mostly now?” I queried, looking up.

”Exactly. That is why, when radium is unprotected or insufficiently protected and comes too near, it is destructive of healthy cells, produces burns, sores, which are most difficult to heal. It is with the explanation of such sores that we must deal.”

It was growing late. We had waited patiently now for some time. Kennedy had evidently reserved this explanation, knowing we should have to wait. Still nothing happened.

Added to the mystery of the violet-colored gla.s.s plate was now that of the luminescent diamond. I was about to ask Kennedy point-blank what he thought of them, when suddenly the little bell before us began to buzz feebly under the influence of a current.

I gave a start. The faithful little selenium cell burglar alarm had done the trick. I knew that selenium was a good conductor of electricity in the light, poor in the dark. Some one had, therefore, flashed a light on one of the cells in the Corporation office. It was the moment for which Kennedy had prepared.

Seizing the round package and the tubing, he dashed out on the street and around the corner. He tried the door opening into the Radium Corporation hallway. It was closed, but unlocked. As it yielded and we stumbled in, up the old worn wooden stairs of the building, I knew that there must be some one there.

A terrific, penetrating, almost stunning odor seemed to permeate the air even in the hall.

Kennedy paused at the door of the office, tried it, found it unlocked, but did not open it.

”That smell is ethyldichloracetate,” he explained. ”That was what I injected into the air cus.h.i.+on of that safe between the two linings. I suppose my man here used an electric drill. He might have used thermit or an oxyacetylene blowpipe for all I would care. These fumes would discourage a cracksman from 'soup' to nuts,” he laughed, thoroughly pleased at the protection modern science had enabled him to devise.

As we stood an instant by the door, I realized what had happened. We had captured our man. He was asphyxiated!

Yet how were we to get to him? Would Craig leave him in there, perhaps to die? To go in ourselves meant to share his fate, whatever might be the effect of the drug.

Kennedy had torn the wrapping off the package. From it he drew a huge globe with bulging windows of gla.s.s in the front and several curious arrangements on it at other points. To it he fitted the rubber tubing and a little pump. Then he placed the globe over his head, like a diver's helmet, and fastened some air-tight rubber arrangement about his neck and shoulders.

”Pump, Walter!” he shouted. ”This is an oxygen helmet such as is used in entering mines filled with deadly gases.”

Without another word he was gone into the blackness of the noxious stifle which filled the Radium Corporation office since the cracksman had struck the unexpected pocket of rapidly evaporating stuff.

I pumped furiously.

Inside I could hear him blundering around. What was he doing?

He was coming back slowly. Was he, too, overcome?

As he emerged into the darkness of the hallway where I myself was almost sickened, I saw that he was dragging with him a limp form.

A rush of outside air from the street door seemed to clear things a little. Kennedy tore off the oxygen helmet and dropped down on his knees beside the figure, working its arms in the most approved manner of resuscitation.

”I think we can do it without calling on the pulmotor,” he panted.

”Walter, the fumes have cleared away enough now in the outside office.

Open a window--and keep that street door open, too.”

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