"No. Heaven knows what the objects of his studies are. But here we are, and you must form your own impressions about him." As he spoke, we turned down a narrow lane and passed through a small side-door, which opened into a wing of the great hospital. It was familiar ground to me, and I needed no guiding as we ascended the bleak stone staircase and made our way down the long corridor with its vista of whitewashed wall and dun-coloured doors. Near the further end a low arched passage branched away from it and led to the chemical laboratory. 
This was a lofty chamber, lined and littered with countless bottles. Broad, low tables were scattered about, which bristled with retorts, test-tubes, and little Bunsen lamps, with their blue flickering flames. There was only one student in the room, who was bending over a distant table absorbed in his work. At the sound of our steps he glanced round and sprang to his feet with a cry of pleasure. "I've found it! I've found it," he shouted to my companion, running towards us with a test-tube in his hand. "I have found a re-agent which is precipitated by hoemoglobin, {4} and by nothing else." Had he discovered a gold mine, greater delight could not have shone upon his features.