“Is it possible you don’t guess?” The sad, hollow eyes questioned my face in surprise. Then they turned haggardly away. “My friend, the other subject associated with Lady Clanbevan in my great experiment was—Her Baby!”

I could not speak. The dowdy little grubs in the flask became for me creatures imbued with dreadful potentialities.... The tragedy and the sublime absurdity of the thing I realized caught at my throat, and my brain grew dizzy with its horror.

“Oh! Professor!” I gurgled, “how—how grimly, awfully, tragically ridiculous! To carry about with one wherever one goes a baby that never grows older—a baby——”

“A baby nearly twenty years old? Yes, it is as you say, ridiculous and horrible,” the Professor agreed.

“What could have induced the woman!” burst from me.

The Professor smiled bitterly.

“She is greedy of money. It is the only thing she loves—except her beauty and her power over men; and during the boy’s infancy—that word is used in the Will—she has full enjoyment of the estate. After he ‘attains to manhood’—I quote the Will again—hers is but a life-interest. Now you understand?”

I did understand, and the daring of the woman dazzled me. She had made the Professor doubly her tool.

“And so,” I gurgled between tears and laughter, “Lord Clanbevan, who ought to be leaving Eton this year to commence his first Oxford term, is being carried about in the arms of a nurse, arrayed in the flowing garments of a six-months’ baby! What an astonishing conspiracy!”

“His mother,” continued the Professor calmly, “allows no one to approach him but the nurse. The family are only too glad to ignore what they consider a deplorable case of atavistic growth-arrest, and the boy himself——” He broke off. “I have detained you,” he said, after a pause. “I will not do so longer. Nor will I offer you my hand. I am as conscious as you are—that it has committed a crime.” And he bowed me out with his hands sternly held behind him. There were few more words between us, only I remember turning on the threshold of the laboratory, where I left him, to ask whether protium—radium, as it is now christened—checks the growth of every organic substance? The answer I received was curious: