"A tumbler of the old Marcobrunner, David, and a slice of the game pie—before I say one word about what we owe to that angel upstairs. Off with the wine, my dear boy; you look as pale as death!"

With those words Mr. Engelman lit his pipe, and waited in silence until the good eating and drinking had done their good work.

"Now carry your mind back to last night," he began. "You remember my going out to get a breath of fresh air. Can you guess what that meant?"

I guessed of course that it meant a visit to Madame Fontaine.

"Quite right, David. I promised to call on her earlier in the day; but poor Keller\'s illness made that impossible. She wrote to me under the impression that something serious must have happened to prevent me, for the first time, from keeping an appointment that I had made with her. When I left you I went to answer her note personally. She was not only distressed to hear of Mr. Keller\'s illness, she was interested enough in my sad news to ask particularly in what form the illness declared itself. When I mentioned what the symptoms were, she showed an agitation which took me quite by surprise. \'Do the doctors understand what is the matter with him?\' she asked. I told her that one of the doctors was evidently puzzled, and that the other had acknowledged that the malady was so far incomprehensible to him. She clasped her hands in despair—she said, \'Oh, if my poor husband had been alive!\' I naturally asked what she meant. I wish I could give her explanation, David, in her own delightful words. It came in substance to this. Some person in her husband\'s employment at the University of Wurzburg had been attacked by a malady presenting exactly the same symptoms from which Mr. Keller was suffering. The medical men had been just as much at a loss what to do as our medical men. Alone among them Doctor Fontaine understood the case. He made up the medicine that he administered with his own hand. Madame Fontaine, under her husband\'s instructions, assisted in nursing the sick man, and in giving the nourishment prescribed when he was able to eat. His extraordinary recovery is remembered in the University to this day."

I interrupted Mr. Engelman at that point. "Of course you asked her for the prescription?" I said. "I begin to understand it now."

"No, David; you don\'t understand it yet. I certainly asked her for the prescription. No such thing was known to be in existence—she reminded me that her husband had made up the medicine himself. But she remembered that the results had exceeded his anticipations, and that only a part of the remedy had been used. The bottle might still perhaps be found at Wurzburg. Or it might be in a small portmanteau belonging to her husband, which she had found in his bedroom, and had brought away with her, to be examined at some future time. \'I have not had the heart to open it yet,\' she said; \'but for Mr. Keller\'s sake, I will look it over before you go away.\' There is a Christian woman, David, if ever there was one yet! After the manner in which poor Keller had treated her, she was as eager to help him as if he had been her dearest friend. Minna offered to take her place. \'Why should you distress yourself, mamma?\' she said. \'Tell me what the bottle is like, and let me try if I can find it.\' No! It was quite enough for Madame Fontaine that there was an act of mercy to be done. At any sacrifice of her own feelings, she was prepared to do it."

I interrupted him again, eager to hear the end.

"And she found the bottle?" I said.

"She found the bottle," Mr. Engelman resumed. "I can show it to you, if you like. She has herself requested me to keep it under lock and key, so long as it is wanted in this house."

He opened an old cabinet, and took out a long narrow bottle of dark-blue glass. In form, it was quaintly and remarkably unlike any modern bottle that I had ever seen. The glass stopper was carefully secured by a piece of leather, for the better preservation, I suppose, of the liquid inside. Down one side of the bottle ran a narrow strip of paper, notched at regular intervals to indicate the dose that was to be given. No label appeared on it; but, examining the surface of the glass carefully, I found certain faintly-marked stains, which suggested that the label might have been removed, ............