For some time the physician gazed in deep thought at the pale face of the unconscious slumberer. Suddenly turning to the Nubian, he said to him: "Ali, where does your master keep the drugs he has been for years accustomed to take?" The Nubian stared in mute amazement, but moved not from his rug. "Ali," said Dr. Orfila, sternly, "unless I see and know those drugs, this night your master dies." The Nubian looked anxiously into the face of the physician, and then, as if satisfied with the scrutiny, rose, and, with noiseless steps, left the room. In a few moments he re-entered and placed in the physician's hands a small casket of ebony, exquisitely worked and studded with gems. Taking it hastily to the shaded lamp upon a table at the extremity of the chamber, he attempted to open it, but his attempts were vain. Indeed, to all appearances, it was a solid block of ebony, and its extreme heaviness, compared with its dimensions, seemed to favor the idea. "Well?" said the doctor, returning the casket, after a close scrutiny, to the Nubian, who had followed him. Ali took the casket, and instantly a portion of the top flew up, disclosing within the centre of the cube of ebony a cavity lined with crimson velvet, and a dazzling array of minute vials of crystal, each filled with a fluid--pink, blue, green and yellow in hue, while the contents of several were colorless. The Nubian had touched a spring concealed in the carving, and known only to his master and himself. The physician removed the minute vials one after another from their receptacles, and held them up to the light; on each was a cipher, and on no two was the same. Most of them were quite filled with the fluid contained, but some were only half full, while one was nearly empty. Dr. Orfila looked closely at the cipher upon each vial as he removed it from the casket. He then held it to the light to determine its particular hue or shade, and sometimes withdrew the crystal stopper ground into the deep mouth, touching it cautiously and quickly to his nostril or the tip of his tongue. "Morphia, cinchonia, quinia, lobelia, belladonna, narcotina, bromine, arsenicum, strychnos colubrina, brucoea ferruginea," muttered the savant, as he examined one vial after the other and replaced it. "Brucoea ferruginea--ha! brucine! I thought as much," exclaimed he, holding up the vial, which showed, by being nearly empty, that its contents had been used more frequently than those of any of the others. "How many drops of this is the greatest number your master has ever taken?" asked Dr. Orfila. The Nubian, who, it will be remembered, was a mute, held up both hands with the fingers outspread, and then two other fingers of one of his hands. "Twelve drops!" cried the astonished physician. "Impossible!" Ali insisted on the assertion. "And yet it must be so," the doctor added. "That would explain all."