Fritz kept the letter from Wurzburg unopened in his hand.

"It\'s not from Minna," he said; "the handwriting is strange to me. Perhaps my father knows something about it." He turned to his father\'s letter; read it; and handed it to me without a word of remark.

Mr. Keller wrote briefly as follows:—

"The enclosed letter has reached me by post, as you perceive, with written instructions to forward it to my son. The laws of honor guide me just as absolutely in my relations with my son as in my relations with any other gentleman. I forward the letter to you exactly as I have received it. But I cannot avoid noticing the postmark of the city in which the Widow Fontaine and her daughter are still living. If either Minna or her mother be the person who writes to you, I must say plainly that I forbid your entering into any correspondence with them. The two families shall never be connected by marriage while I live. Understand, my dear son, that this is said in your own best interests, and said, therefore, from the heart of your father who loves you."

While I was reading these lines Fritz had opened the letter from Wurzburg. "It\'s long enough, at any rate," he said, turning over the closely-written pages to find the signature at the end.

"Well?" I asked.

"Well," Fritz repeated, "it\'s an anonymous letter. The signature is \'Your Unknown Friend.\'"

"Perhaps it relates to Miss Minna, or to her mother," I suggested. Fritz turned back to the first page and looked up at me, red with anger. "More abominable slanders! More lies about Minna\'s mother!" he burst out. "Come here, David. Look at it with me. What do you say? Is it the writing of a woman or a man?"

The writing was so carefully disguised that it was impossible to answer his question. The letter (like the rest of the correspondence connected with this narrative) has been copied in duplicate and placed at my disposal. I reproduce it here for reasons which will presently explain themselves—altering nothing, not even the vulgar familiarity of the address.

"My good fellow, you once did me a kindness a long time since. Never mind what it was or who I am. I mean to do you a kindness in return. Let that be enough.

"You are in love with \'Jezebel\'s Daughter.\' Now, don\'t be angry! I know you believe Jezebel to be a deeply-injured woman; I know you have been foolish enough to fight duels at Wurzburg in defense of her character.

"It is enough for you that she is a fond mother, and that her innocent daughter loves her dearly. I don\'t deny that she is a fond mother; but is the maternal instinct enough of itself to answer for a woman? Why, Fritz, a cat is a fond mother; but a cat scratches and swears for all that! And poor simple little Minna, who can see no harm in anybody, who can\'t discover wickedness when it stares her in the face—is she a trustworthy witness to the widow\'s character? Bah!

"Don\'t tear up my letter in a rage; I am not going to argue the question with you any further. Certain criminal circumstances have come to my knowledge, which point straight to this woman. I shall plainly relate those circumstances, out of my true regard for you, in the fervent hope that I may open your eyes to the truth.

"Let us go back to the death of Doctor-Professor Fontaine, at his apartments in the University of Wurzburg, on the 3rd of September, in the present year 1828.

"The poor man died of typhoid fever, as you know—and died in debt, through no extravagance on his own part, as you also know. He had outlived all his own relatives, and had no pecuniary hopes or expectations from anyone. Under these circumstances, he could only leave the written expression of his last wishes, in place of a will.

"This document committed his widow and child to the care of his widow\'s relations, in terms of respectful entreaty. Speaking next of himself, he directed that he should be buried with the strictest economy, so that he might cost the University as little as possible. Thirdly, and lastly, he appointed one of his brother professors to act as his sole executor, in disposing of those contents of his laboratory which were his own property at the time of his death.

"The written instructions to his executor are of such serious importance that I feel it my duty to copy them for you, word for word.

"Thus they begin:—

"\'I hereby appoint my dear old friend and colleague, Professor Stein—now absent for a while at Munich, on University business—to act as my sole representative in the disposal of the contents of my laboratory, after my death. The various objects used in my chemical investigations, which are my own private property, will be all found arranged on the long deal table that stands between the two windows. They are to be offered for sale to my successor, in the first instance. If he declines to purchase them, they can then be sent to Munich, to be sold separately by the manufacturer, as occasion may offer. The furniture of the laboratory, both movable and stationary, belongs entirely to the University, excepting the contents of an iron safe built into the south wall of the room. As to these, which are my own sole property, I seriously enjoin my executor and representative to follow my instructions to the letter:—

"\'(1) Professor Stein will take care to be accompanied by a competent witness, when he opens the safe in the wall.

"\'(2) The witness will take down in writing, from the dictation of Professor Stein, an exact list of the contents of the safe. These are:—Bottles containing drugs, tin cases containing powders, and a small medicine-chest, having six compartments, each occupied by a labeled bottle, holding a liquid preparation.

"\'(3) The written list being complete, I desire Professor Stein to empty every one of the bottles and cases, including the bottles in the medicine-chest, into the laboratory sink, with his own hands. He is also to be especially careful to destroy the labels on the bottles in the medicine-chest. These things done, he will sign the list, stating that the work of destruction is accomplished; and the witness present will add his signature. The document, thus attested, is to be placed in the care of the Secretary to the University.

"\'My object in leaving these instructions is simply to prevent the dangerous results which might follow any meddling with my chemical preparations, after m............