Mueller came and looked down at it over my shoulder.

“It is an interesting head,” said he.  “I have a great mind to introduce it into my next year’s competition picture.”

I started as if he had struck me.  The thought was sacrilege!

“For Heaven’s sake do no such thing!” I ejaculated.

“Why not?” said he, opening his eyes in astonishment.

“I cannot tell you why—­at least not yet; but to—­to confer a very particular obligation upon me, will you waive this point?” Mueller rubbed his head all over with both hands, and sat down in the utmost perplexity.

“Upon my soul and conscience,” said he, “you are the most incomprehensible fellow I ever knew in my life!”

“I am.  I grant it.  What then?  Let us see, I am to give you a hundred and fifty francs for this copy ...”

“I won’t take it,” said Mueller.  “I mean you to accept it as a pledge of friendship and good-will.”

“Nay, I insist on paying for it.  I shall be proud to pay for it; but a hundred and fifty are not enough.  Let me give you three hundred, and promise me that you will not put the head into your picture!”

Mueller laughed, and shook his own head resolutely.  “I will give you both the portrait and the promise,” said he; “but I won’t take your money, if I know it.”

“But ...”

“But I won’t—­and so, if you don’t like me well enough to accept such a trifle from me, I’ll e’en carry the thing home again!”

And, snatching up his cap and cloak, he made a feint of putting the portrait back into the folio.

“Not for the world!” I exclaimed, taking possession of it without further remonstrance.  “I would sooner part from all I possess.  How can I ever thank you enough?”

“By never thanking me at all!  What little time the thing has cost me is overpaid, not only by the sight of your pleasure, but by my own satisfaction in copying it.  To copy a good work is to have a lesson from the painter, though he were dead a hundred years before; and the man who painted that portrait, be he who he might, has taught me a trick or two that I never knew before. Sapristi! see if I don’t dazzle you some day with an effect of white satin and pearls against a fair skin!”

“An ingenious argument; but it leaves me unconvinced, all the same.  How! you are not going to run away already?  Here’s another bottle of Chambertin waiting to be opened; and it is yet quite early.”

“Impossible!  I have promised to meet a couple of men up at the Prado, and have, besides, invited them afterwards to supper.”

“What is the Prado?”

“The Prado!  Why, is it possible that I have never yet introduced you to the Prado?  It’s one of the joiliest places in all the Quartier Latin—­it’s close to the Palais de Justice.  You can dance there, or practise pistol-shooting, or play billiards, or sup—­or anything you please.  Everybody smokes—­ladies not excepted.”