“And it goes twice?” I said, nearing his doorway in a grateful perspiration.

“It goes a thousand times, many thousand times!” cried Gibberne, with a dramatic gesture, flinging open his Early English carved oak gate.

“Phew!” said I, and followed him to the door.

“I don’t know how many times it goes,” he said, with his latch-key in his hand.

“And you——­”

“It throws all sorts of light on nervous physiology, it kicks the theory of vision into a perfectly new shape! ...  Heaven knows how many thousand times.  We’ll try all that after——­The thing is to try the stuff now.”

“Try the stuff?” I said, as we went along the passage.

“Rather,” said Gibberne, turning on me in his study.  “There it is in that little green phial there!  Unless you happen to be afraid?”

I am a careful man by nature, and only theoretically adventurous.  I was afraid.  But on the other hand, there is pride.

“Well,” I haggled.  “You say you’ve tried it?”

“I’ve tried it,” he said, “and I don’t look hurt by it, do I?  I don’t even look livery, and I feel——­”

I sat down.  “Give me the potion,” I said.  “If the worst comes to the worst it will save having my hair cut, and that, I think, is one of the most hateful duties of a civilised man.  How do you take the mixture?”

“With water,” said Gibberne, whacking down a carafe.

He stood up in front of his desk and regarded me in his easy-chair; his manner was suddenly affected by a touch of the Harley Street specialist.  “It’s rum stuff, you know,” he said.

I made a gesture with my hand.

“I must warn you, in the first place, as soon as you’ve got it down to shut your eyes, and open them very cautiously in a minute or so’s time.  One still sees.  The sense of vision is a question of length of vibration, and not of multitude of impacts; but there’s a kind of shock to the retina, a nasty giddy confusion just at the time if the eyes are open.  Keep ’em shut.”

“Shut,” I said.  “Good!”

“And the next thing is, keep still.  Don’t begin to whack about.  You may fetch something a nasty rap if you do.  Remember you will be going several thousand times faster than you ever did before, heart, lungs, muscles, brain—­everything—­and you will hit hard without knowing it.  You won’t know it, you know.  You’ll feel just as you do now.  Only everything in the world will seem to be going ever so many thousand times slower than it ever went before.  That’s what makes it so deuced queer.”

“Lor,” I said.  “And you mean——­”

“You’ll see,” said he, and took up a little measure.  He glanced at the material on his desk.  “Glasses,” he said, “water.  All here.  Mustn’t take too much for the first attempt.”

The little phial glucked out its precious contents.  “Don’t forget what I told you,” he said, turning the contents of the measure into a glass in the manner of an Italian waiter measuring whisky.  “Sit with the eyes tightly shut and in absolute stillness for two minutes,” he said.  “Then you will hear me speak.”