It was just then that Boyce came in.  So soon as he spoke Davidson exclaimed:  “Old Boyce!  Dead too!  What a lark!” I hastened to explain that Davidson was in a kind of somnambulistic trance.  Boyce was interested at once.  We both did all we could to rouse the fellow out of his extraordinary state.  He answered our questions, and asked us some of his own, but his attention seemed distracted by his hallucination about a beach and a ship.  He kept interpolating observations concerning some boat and the davits, and sails filling with the wind.  It made one feel queer, in the dusky laboratory, to hear him saying such things.

He was blind and helpless.  We had to walk him down the passage, one at each elbow, to Boyce’s private room, and while Boyce talked to him there, and humoured him about this ship idea, I went along the corridor and asked old Wade to come and look at him.  The voice of our Dean sobered him a little, but not very much.  He asked where his hands were, and why he had to walk about up to his waist in the ground.  Wade thought over him a long time—­you know how he knits his brows—­and then made him feel the couch, guiding his hands to it.  “That’s a couch,” said Wade.  “The couch in the private room of Professor Boyce.  Horse-hair stuffing.”

Davidson felt about, and puzzled over it, and answered presently that he could feel it all right, but he couldn’t see it.

“What do you see?” asked Wade.  Davidson said he could see nothing but a lot of sand and broken-up shells.  Wade gave him some other things to feel, telling him what they were, and watching him keenly.

“The ship is almost hull down,” said Davidson presently, apropos of nothing.

“Never mind the ship,” said Wade.  “Listen to me, Davidson.  Do you know what hallucination means?”

“Rather,” said Davidson.

“Well, everything you see is hallucinatory.”

“Bishop Berkeley,” said Davidson.

“Don’t mistake me,” said Wade.  “You are alive and in this room of Boyce’s.  But something has happened to your eyes.  You cannot see; you can feel and hear, but not see.  Do you follow me?”

“It seems to me that I see too much.”  Davidson rubbed his knuckles into his eyes.  “Well?” he said.

“That’s all.  Don’t let it perplex you.  Bellows here and I will take you home in a cab.”

“Wait a bit.”  Davidson thought.  “Help me to sit down,” said he presently; “and now—­I’m sorry to trouble you—­but will you tell me all that over again?”

Wade repeated it very patiently.  Davidson shut his eyes, and pressed his hands upon his forehead.  “Yes,” said he.  “It’s quite right.  Now my eyes are shut I know you’re right.  That’s you, Bellows, sitting by me on the couch.  I’m in England again.  And we’re in the dark.”

Then he opened his eyes.  “And there,” said he, “is the sun just rising, and the yards of the ship, and a tumbled sea, and a couple of birds flying.  I never saw anything so real.  And I’m sitting up to my neck in a bank of sand.”