Leslie had flashed up the light again before Craig spoke.  We were all watching him keenly.

“Phosphorus, phosphoric acid, or phosphoric salve,” Craig said slowly, looking eagerly about the room as if in search of something that would explain it.  He caught sight of the envelope still lying on the dresser.  He picked it up, toyed with it, looked at the top where O’Connor had slit it, then deliberately tore the flap off the back where it had been glued in sealing the letter.

“Put the light out again,” he asked.

Where the thin line of gum was on the back of the flap, in the darkness there glowed the same sort of brightness that we had seen in a speck here and there on Blanche Blaisdell’s lips and in her mouth.  The truth flashed over me.  Some one had placed the stuff, whatever it was, on the flap of the envelope, knowing that she must touch her lips to it to seal it She had done so, and the deadly poison had entered her mouth.

As the light went up again Kennedy added:  “Oil of turpentine removes traces of phosphorus, phosphoric acid, or phosphoric salve, which are insoluble in anything else except ether and absolute alcohol.  Some one who knew that tried to eradicate them, but did not wholly succeed.  O’Connor, see if you can find either phosphorus, the oil, or the salve anywhere in the shop.”

Then as O’Connor and Leslie hurriedly disappeared he added to me:  “Another of those strange coincidences, Walter.  You remember the girl at the hospital?  ’Look, don’t you see it?  She’s afire.  Her lips shine—­they shine, they shine!’”

Kennedy was still looking carefully over the room.  In a little wicker basket was a newspaper which was open at the page of theatrical news, and as I glanced quickly at it I saw a most laudatory paragraph about her.

Beneath the paper were some torn scraps.  Kennedy picked them up and pieced them together.  “Dearest Blanche,” they read.  “I hope you’re feeling better after that dinner last night.  Can you meet me to-night?  Write me immediately.  Collie.”

He placed the scraps carefully in his wallet.  There was nothing more to be done here apparently.  As we passed down the corridor we could hear a man apparently raving in good English and bad French.  It proved to be Millefleur—­or Miller—­and his raving was as overdone as that of a third-rate actor.  Madame was trying to calm him.

“Henri, Henri, don’t go on so,” she was saying.

“A suicide—­in the Novella.  It will be in all the papers.  We shall be ruined.  Oh—­oh!”

“Here, can that sob stuff,” broke in one of O’Connor’s officers.  “You can tell it all when the chief takes you to headquarters, see?”

Certainly the man made no very favourable impression by his actions.  There seemed to be much that was forced about them, that was more incriminating than a stolid silence would have been.