“Would your Eminence put a question to him on some very important matter?  Something that would have made a deep impression.”

The Cardinal considered.

“Well,” he said, “yes.  Do you remember the message brought by special messenger from Windsor yesterday evening?”

Monsignor shook his head.

“That’ll do,” said the doctor.  “Don’t attempt to force yourself.”

He rose from his chair, fetched his bag and opened it.  Out of it he took an instrument rather resembling a small camera, but with a bundle of minute wires of some very pliable material, each ending in a tiny disc.

“Do you know what this is, Monsignor?” asked the doctor, busying himself with the wires.

“I have no idea.”

“Well, well. . . .  Now, Monsignor, kindly loosen your waistcoat, so that I can get at your breast and back.”

“Is it a stethoscope?”

“Something like it,” smiled the doctor.  “But how did you know that name?  Never mind.  Now then, please.”

He placed the camera affair on the corner of the table near the arm-chair; and then, very rapidly, began to affix the discs—­it seemed by some process of air-exhaustion—­all over the head, breast, and back of the amazed man.  No sensation followed this at all, except the very faint feeling of skin-contraction at each point of contact.

“May I have that blind down, your Eminence? . . .  Ah! that’s better.  Now then.”

He bent closely over the square box on the table, and seemed to peer at something inside.  The others kept silence.

“Well?” asked the Cardinal at last.

“Perfectly satisfactory, your Eminence.  There is a very faint discoloration, but no more than is usual in a man of Monsignor’s temperament at any excitement.  There is absolutely nothing wrong, and—­Monsignor,” he continued, looking straight at the wire-bedecked invalid, “not the very faintest indication of anything even approaching insanity or imbecility.”

The man who had lost his memory drew a swift breath.

“May I see, doctor?” asked the Cardinal suavely.

“Certainly, your Eminence; and Monsignor can look himself, if he likes.”

When the other two had looked, the sick man himself was given the box.

“(Carefully with that wire, please.) There!” said the doctor.  “Look down there.”

In the centre of the box, shielded by a little plate of glass, there appeared a small semi-luminous globe.  This globe seemed tinted with slightly wavering colours, in which a greyish blue predominated; but, almost like a pulse, there moved across it from time to time a very pale red tint, suffusing it, and then dying away again.

“What is it?” asked the man in the chair hoarsely, lifting his head.

“That, my dear Monsignor,” explained the doctor carefully, “is a reflection of your physical condition.  It is an exceedingly simple, though of course very delicate instrument.  The method was discovered—–­”