The next morning, when Mr. Crowe heard the report of the evening’s work—the nature of the long course of investigations, the Russian treatise which had fallen so strangely into his assistant’s hands, the discovery of the tests and the other points that indicated, as by the finger of an avenging angel, his guilt and downfall—he knew Mole was on his track, knew that he was in his power, and that his doom had come. He was alone with his crime; his murdered wife was avenged. He turned from his pupils, who eagerly questioned him as to his opinion on this and the other points of Mole’s paper, went into his laboratory, seized a bottle of prussic acid, drank its contents, and was a corpse before his class had left the lecture theatre. Everybody attributed the awful tragedy to jealousy of Mole’s success. Two men knew the secret, and kept it. Two women guessed it, and told their suspicions. Gradually, like a bad vapour spread by the law of diffusion of gases, all the world had an inkling of the crime. But Mole and Sones held their peace; and when the former was elected to the vacant chair of physiology at St. Bernard’s, there was only one man besides the occupier of the post who knew the steps by which it had been reached. Mr. Mole proved a failure; his great monograph was all the original work he ever did, and he lived a poor and obscure man. He never married Janet, after all, so that her Egyptian gentleman misled her no less than the little physiologist. Dr. Sones still occupies his old quarters, and now and then gets a thrill of ecstatic delight as he makes some new discovery in his favourite study; and though he does not acquire a fortune, he gets what he values more—a little fame from time to time in the chemical journals of Europe. His good sister still befriends his poor clients; and even his Board of Guardians acknowledges that, in the medical officer of the south ward of their parish and his estimable sister, they have full value for the salary they pay their doctor. This has actually been admitted at the Board, and nobody opposed it—a fact going far to prove that the officer must either be a very good or an exceedingly bad one. * * * * *