Slack nodded wearily, while the Doctor unlocked a black cabinet and took from thence a brittle flask and a liqueur glass. He held the flask up to the light before Slack's face. The liquid flamed yellow in the gaslight. It seemed to have concentrated in its ebullient elements the exhilaration of life. Now, the yellow cordial, even as the inebriate looked upon it, glowed and became incandescent. It seemed to be endowed with its own principle of energy. Harland Slack started up, and looked at this phenomenon more closely with intelligent astonishment. "This," said Dr. Alaric Randolph observantly, "is the issue of many laborious years abroad. This is the theriaca against all vital poisons. Watch it; for even as you look upon it, you absorb its virtue." There was no melodrama in the Doctor's action or accent. He spoke quite naturally. Harland was as much impressed by his friend's sincerity as by the singular appearance of this _elixir vitae_. He did not need to be urged to look at the glass again. It was a fountain of boiling light. At this moment, a knock was heard at that door of the reception room which evidently led into the Doctor's inner office. Dr. Randolph started, quickly locked the door leading into the hall, and put the priceless flask gently upon a high bookcase. It was on a level with his face. The liquid shot bubbles of animation to the surface; and before Slack's eyes, as if gathering fire from the light or the heat, it slowly began to turn red. The languid debauchee now jumped nimbly to his feet and stood entranced before this beautiful, perplexing transformation. "Keep your eyes on it for a moment, my friend," whispered Dr. Randolph: "watch it carefully for me. I wish to note its changes. It differs under variable conditions. Tell me about it. Do not touch it. When I come back you shall taste, and then--" Harland lost the last words as the physician hurried out.