"Is this the glove your master wore when he went to The Hague?" I asked, selecting the left-hand one. "Yes, sir." I examined it closely and very gingerly. The exterior presented nothing out of the ordinary, but on turning it inside out, I found in the index finger a tiny piece of steel which tumbled out upon the table. It was apparently a piece clipped from the blade of a safety razor, and keenly sharp. Anyone inserting a finger into the glove would certainly be cut by the razor edge of that sharp scrap of steel. As it lay upon the polished oak I bent to look at it, the valet also standing near and bending down in curiosity. Upon it something had apparently been smeared--some colourless jelly, it seemed. Had Baron van Veltrup fallen victim to orosin, wilfully administered? That was my instant suspicion, one that was afterwards verified by the great Dutch pathologist Doctor Obelt, who lived in the Amstel Straat, and to whom I carried the mysterious but incriminating scrap of steel. "Without a doubt this piece of razor-blade has been impregnated with a new and most deadly poison, orosin," he declared to me on the following evening as I sat in his consulting room. "The police have seen no mysterious circumstances in the unfortunate death of the Baron, who, by the way, was a very dear friend of mine. But now you have brought me this piece of steel which you took from his glove, and which no doubt must have caused a slight cut to his finger and, in consequence, almost instant death, I feel it my duty to take up the matter with the authorities." "I shall be much gratified, doctor, if you will," I urged, speaking in French. "The valet's suspicions of foul play are entirely proved." "Yes, foul play, committed by somebody who possesses expert toxicological knowledge. I confess that this is the first time I have discovered orosin. The hint you gave me caused me to search for it, and that I have found it is undoubted." Later that day I accompanied the doctor to the Bureau of Police, where we were met by a very stolid official who smoked a long thin cigar all the time he talked to us. At first he treated the affair as of no importance. The medical evidence had pronounced the Baron's death as having been due to natural causes. The police could not interfere further, he declared. "Ah! but thanks to the Baron's valet we now have evidence of a most subtle and deadly poison," declared the Dutch pathologist. "I certify that I have found upon a small piece of sharp steel, which has been discovered in the dead man's glove, traces of orosin, one of the least known but most dangerous poisons." The heavy-jowled Dutch police official straightened himself in his chair. "Is that really so, doctor?" he asked in surprise, holding his cigar between his fingers.