“Come, Alan, you must decide at once.”

“I cannot do it,” he said, mechanically, as though words could alter things.

“You must.  You have no choice.  Don’t delay.”

He hesitated a moment.  “Is there a fire in the room upstairs?”

“Yes, there is a gas-fire with asbestos.”

“I shall have to go home and get some things from the laboratory.”

“No, Alan, you must not leave the house.  Write out on a sheet of notepaper what you want and my servant will take a cab and bring the things back to you.”

Campbell scrawled a few lines, blotted them, and addressed an envelope to his assistant.  Dorian took the note up and read it carefully.  Then he rang the bell and gave it to his valet, with orders to return as soon as possible and to bring the things with him.

As the hall door shut, Campbell started nervously, and having got up from the chair, went over to the chimney-piece.  He was shivering with a kind of ague.  For nearly twenty minutes, neither of the men spoke.  A fly buzzed noisily about the room, and the ticking of the clock was like the beat of a hammer.

As the chime struck one, Campbell turned round, and looking at Dorian Gray, saw that his eyes were filled with tears.  There was something in the purity and refinement of that sad face that seemed to enrage him.  “You are infamous, absolutely infamous!” he muttered.

“Hush, Alan.  You have saved my life,” said Dorian.

“Your life?  Good heavens! what a life that is!  You have gone from corruption to corruption, and now you have culminated in crime.  In doing what I am going to do—­what you force me to do—­ it is not of your life that I am thinking.”

“Ah, Alan,” murmured Dorian with a sigh, “I wish you had a thousandth part of the pity for me that I have for you.”  He turned away as he spoke and stood looking out at the garden.  Campbell made no answer.

After about ten minutes a knock came to the door, and the servant entered, carrying a large mahogany chest of chemicals, with a long coil of steel and platinum wire and two rather curiously shaped iron clamps.

“Shall I leave the things here, sir?” he asked Campbell.

“Yes,” said Dorian.  “And I am afraid, Francis, that I have another errand for you.  What is the name of the man at Richmond who supplies Selby with orchids?”

“Harden, sir.”

“Yes—­Harden.  You must go down to Richmond at once, see Harden personally, and tell him to send twice as many orchids as I ordered, and to have as few white ones as possible.  In fact, I don’t want any white ones.  It is a lovely day, Francis, and Richmond is a very pretty place—­ otherwise I wouldn’t bother you about it.”

“No trouble, sir.  At what time shall I be back?”

Dorian looked at Campbell.  “How long will your experiment take, Alan?” he said in a calm indifferent voice.  The presence of a third person in the room seemed to give him extraordinary courage.