It was the speaking-tube!
He clung to it with the remnant of his strength and eagerly placed his lips to the mouthpiece. For a few minutes he drank in with avidity the revivifying draughts of air which gradually brought him back from the brink of death.
With returning consciousness, the thought of his dying friend recurred to him in all its vividness. He tried to go to his assistance; but he was sick and faint, and his limbs were powerless to respond to his will. Then, at last, he was seized with utter despair and gave up the struggle.
He had sunk dejectedly upon the chair when a faint and indistinct murmur, as of distant voices, beat upon his ears, whose natural acuity seemed extraordinarily increased by the long nervous tension under which he had been. The ruling passion is strong in death; without knowing just why he did so, Sturgis found himself again at the speaking-tube, endeavoring to hear the conversation, the sound of which evidently came from Murdock's office.
He could barely distinguish a word here and there; but he recognized the timbre of one of the voices. It was the chemist's, and his interlocutor was a woman—perhaps his daughter. If only he could reach Agnes Murdock with some word or signal.
In suspense, he held his ear to the mouthpiece, occasionally taking a breath of fresh air to renew his strength.
Should he take the chances and shout in the hope of catching the young girl's attention? If he whistled, Murdock would answer himself, and the last chance would be lost. But would she hear a shout? And, if she did, would not her father prevent her from rendering any assistance? Yet what other chance was there? Poor Sprague was dying; perhaps already dead. There was no time to lose.
He stood for a while irresolute, and had just made up his mind to risk all on a bold move, when suddenly Murdock's voice became more distinct, as if he were passing near the mouthpiece of the speaking-tube at the other end.
"I shall be back directly."
He was going, then. Agnes, if it were she, would remain alone for at least an instant; and in that instant lay possible salvation.