Gonsalez sprang to his feet, his eyes blazing.
"What a fool! What a fool!" he almost shouted. "I didn't see those. Are you sure, George?" he asked eagerly. "He had thick gloves? Are you certain?"
Manfred nodded, smiling his surprise at the other's perturbation.
"That's it!" Gonsalez snapped his fingers. "I knew there was some error in my calculations! Thick woollen gloves, weren't they?" He became suddenly thoughtful. "Now, I wonder how the devil he induced the old man to put 'em on?" he said half to himself.
The request to Mr. Fare was granted, and the two men went together to the laboratory. John Munsey was waiting for them.
"I discovered those spectacles by my uncle's bedside," he said as soon as he saw them.
"Oh, the spectacles?" said Leon absently. "May I see them?" He took them in his hand. "Your uncle was very short-sighted. How did they come to leave his possession, I wonder?"
"I think he went up to his bedroom to change; he usually did after dinner," explained Mr. Munsey. "And he must have left them there. He usually kept an emergency pair in the laboratory, but for some reason or other he doesn't seem to have put them on. Do you wish to be alone in the laboratory?" he asked.
"I would rather," said Leon. "Perhaps you would entertain my friend whilst I look round?"
Left alone, he locked the door that communicated between the laboratory and the house, and his first search was for the spectacles that the old man usually wore when he was working.
Characteristically enough, he went straight to the place where they were—a big galvanised ash-pan by the side of the steps leading up to the laboratory. He found them in fragments, the horn rims broken in two places, and he collected what he could and returned to the laboratory, and, laying them on the bench, he took up the telephone.
The laboratory had a direct connection with the exchange, and after five minutes waiting, Gonsalez found himself in communication with Stephen Tableman.
"Yes, sir," was the surprised reply. "My father wore his glasses throughout the interview."
"Thank you, that is all," said Gonsalez and hung up the 'phone.
Then he went to one of the apparatus in a corner of the laboratory and worked steadily for an hour and a half. At the end of that time he went to the telephone again. Another half hour passed, and then he pulled from his pocket a pair of thick woollen gloves, and unlocking the door leading to the house, called Manfred.
"Ask Mr. Munsey to come," he said.
"Your friend is interested in science," said Mr. Munsey as he accompanied Manfred along the passage.
"I think he is one of the cleverest in his own particular line," said Manfred.
He came into the laboratory ahead of Munsey, and to his surprise, Gonsalez was standing near the table, holding in his hand a small liqueur glass filled with an almost colourless liquid. Almost colourless, but there was a blue tinge to it, and to Manfred's amazement a faint mist was rising from its surface.
Manfred stared at him, and then he saw that the hands of Leon Gonsalez were enclosed in thick woollen gloves.
"Have you finished?" smiled Mr. Munsey as he came from behind Manfred; and then he saw Leon and smiled no more. His face went drawn and haggard, his eyes narrowed, and Manfred heard his laboured breathing.
"Have a drink, my friend?" said Leon pleasantly. "A beautiful drink. You'd mistake it for crème de menthe or any old liqueur—especially if you were a short-sighted, absent-minded old man and somebody had purloined your spectacles."
"What do you mean?" asked Munsey hoarsely. "I—I don't understand you."
"I promise you that this drink is innocuous, that it contains no poison whatever, that it is as pure as the air you breathe," Gonsalez went on.
"Damn you!" yelled Munsey, but before he could leap at his tormentor, Manfred had caught him and slung him to the ground.
"I have telephoned for the excellent Mr. Fare, and he will be here soon, and also Mr. Stephen Tableman. Ah, here they are."
There was a tap at the door.
"Will you open, please, my dear George? I do not think our young friend will move. If he does, I will throw the contents of this glass in his face."
Fare came in, followed by Stephen, and with them an officer from Scotland Yard.
"There is your prisoner, Mr. Fare," said Gonsalez. "And here is the means by which Mr. John Munsey encompassed the death of his uncle—decided thereto, I guess, by the fact that his uncle had been reconciled with Stephen Tableman, and that the will which he had so carefully manœuvred was to be altered in Stephen Tableman's favour."
"That's a lie!" gasped John Munsey. "I worked for you—you know I did, Stephen. I did my best for you——"
"All part of the general scheme of deception—again I am guessing," said Gonsalez. "If I am wrong, drink this. It is the liquid your uncle drank on the night of his death."
"What is it?" demanded Fare quickly.
"Ask him," smiled Gonsalez, nodding to the man.
John Munsey turned on his heels and walked to the door, and the police officer who had accompanied Fare followed him.
"And now I will tell you what it is," said Gonsalez. "It is liquid air!"
"Liquid air!" said the Commissioner. "Why, what do you mean? How can a man be poisoned with liquid air?"
"Professor Tableman was not poisoned. Liquid air is a fluid obtained by reducing the temperature of air to two hundred and seventy degrees below zero. Scientists use the liquid for experiments, and it is usually kept in a thermos flask, the mouth of which is stopped with cotton wool, because, as you know, there would be danger of a blow up if the air was confined."
"Good God?" gasped Tableman in horror. "Then that blue mark about my father's throat——?"
"He was frozen to death. At least his throat was frozen solid the second that liquid was taken. Your father was in the habit of drinking a liqueur before he went to bed, and there is no doubt that, after you had left, Munsey gave the Professor a glassful of liquid air and by some means induced him to put on gloves."
"Why did he do that? Oh, of course, the cold," said Manfred.
Gonsalez nodded.
"Without gloves he would have detected immediately the stuff he was handling. What artifice Munsey used we may never know. It is certain he himself must have been wearing gloves at the time. After your father's death he then began to prepare evidence to incriminate somebody else. The Professor had probably put away his glasses preparatory to going to bed, and the murderer, like myself, overlooked the fact that the body was still wearing gloves.
"My own theory," said Gonsalez later, "is that Munsey has been working for years to oust his cousin from his father's affections. He probably invented the story of the dipsomaniac father of Miss Faber."
Young Tableman had come to their lodgings, and now Gonsalez had a shock. Something he said had surprised a laugh from Stephen, and Gonsalez stared at him.
"Your—your teeth!" he stammered.
Stephen flushed.
"My teeth?" he repeated, puzzled.
"You had two enormous canines when I saw you last," said Gonsalez. "You remember, Manfred?" he said, and he was really agitated. "I told you——"
He was interrupted by a burst of laughter from the young student.