Lastly, he astounded his old colleague by proposing to administer an emetic.

There was no prevailing on him to give his reasons.

"If I prove to be right, you shall hear my reasons.

If I prove to be wrong, I have only to say so, and no reasons will be required.

Clear the room, administer the emetic, and keep the door locked till I come back." With those parting directions he hurried out of the house.
"What _can_ he mean ?" said Mr.Engelman, leading the way out of the bedchamber.
The elder doctor left in charge heard the words, and answered them, addressing himself, not to Mr.Engelman, but to me.