I could hear a gasp from the auditors and I knew that someone's heart must be icy at the discovery of the portentous secret.
"I have some liquid air in this Dewar flask," continued Kennedy. "That is what liquid air is usually kept in. But it may be kept in an ordinary thermos bottle quite well, also.
"If I should drop just a minute bit on my hand, it would probably boil away without hurting me, for it evaporates so quickly that it forms a layer or film of air which prevents contact of the terribly cold liquid air and the skin. I might thrust my finger in it for a few seconds and it would not hurt me. But if I kept it there my finger would become brittle and actually break off, so terrible is the cold of one hundred and ninety degrees below zero, Centigrade. It produces an instantaneous frost bite, numbing so quickly that it often is hardly felt. Placed on the surface of flesh this way, it changes it to a pearly-white, solid surface. The thawing, however, is intensely painful, giving first a burning sensation, then a stinging, flushed feeling, exactly as Irving Evans described what he felt. The part affected swells and a crust forms which it takes weeks to heal, supposing the part affected is small.
"Someone, in that locker-room," continued Craig, "placed a piece of cotton soaked in liquid air on the stomach of the unconscious boy. Instantly, before anyone noticed it, it froze through to the solar plexus. Ultimately that was bound to kill him. And who would bear the blame? Why, Fraser Ferris, of course. The accident in the bout afforded an opportunity to use the stuff which the criminal in his wildest dreams could not have bettered."
"How about Benson, the steward?" spoke up a voice.
We turned. It was the Coroner, loath even yet to give up the official theory.
"That was a pure accident," returned Kennedy. "The club, as you know, is a temperance club. But the members, or at least some of them, keep drinks in their lockers. The steward, Benson, knew this. It has been shown that Benson had been in town that evening, had imbibed considerably.
"He had observed one of the members of the club take from his locker something which he thought was to revive young Evans. What more natural, then, than for him to visit that locker when he returned from town, open it?
"He found a thermos bottle. Instead of the regular cork, it had a light cotton stopper. In his muddled state, the steward did not stop to think—even if he had, he would have seen no reason for carefully corking something that was not designed to keep in a thermos bottle.
"But instead of whiskey, the bottle contained what had not yet evaporated of the liquid air. You may not know it, but liquid air can be easily preserved in open vessels with a stopper which allows the passage of the evaporated air. However paradoxical it may seem, it cannot be kept in closed vessels, for enormous pressures are at once brought into play.