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---" "Is it anything to do with magnetism ?" "They used to call it that, I think.

It's got several names now.
All mental disturbance has, of course, a physical side to it, and that is how we are able to record it physically.