Hamerly looked up. “That’s about right, Orrington. Or better yet, you could say it bends the things you see, as the hot gases rising from a chimney bend everything behind them into wavy lines. Haven’t you ever watched the queer waviness that shows in a wintry atmosphere above chimneys, when you look over them?” “Many a time,” I replied. “Well, that’s just the same type of thing we have here. When you look across a chimney, where hot gases from a fire are coming off, you are looking from air through lighter gases (for such hot gases are lighter than cold air) to cold air again. That extreme bending of light rays that we call refraction is the reason why we hope we have a new gas.” “If we can test the gas to find out what it is, it ought to be a big lift in finding out what really happened,” I said, as I descended from the table. “That won’t be hard at all,” interrupted Dorothy. “We’ll test it with the spectroscope in the next room. Here comes Tom now, with the apparatus to catch and confine the gas.” With glass tubes and air pumps, with platinum and flame, they strove for half an hour, Tom, Hamerly, and Swenton together. Dorothy threw in a quiet word of suggestion now and then, but the most of the time she stood back with me. This was a matter for experts, and left nothing for me to do. As we waited, I asked Dorothy two questions. “Where do you think the gas came from? Has it been here since Heidenmuller’s death?” “I think it must have been,” answered Dorothy. “If, as I imagine, we have an unknown gas here, it is probably one of the products left behind from the metal destroyed by the terrific force used by the man. When the substance that gave the force, energy, or whatever you call it, escaped through the broken valve of the cigarette case, this gas was formed from the changed metal and, as it was lighter than the air, some of it rose and filled the shade, the rest floated upward and out through some crevice. When the man destroyed the Alaska or any of the other vessels, the same thing probably occurred--the metal of the ship changed to a gas which floated up into the air with extreme rapidity. The gas must be to air as oil is to water, that is, it can’t diffuse or mix with it, any more than oil can mix with water. Otherwise it wouldn’t have stayed all these months in the lamp shade.” Just then Tom came towards us with a glass tube, a foot long and an inch or two wide, in his hand. In each end was sealed a bit of silvery metal. “Platinum,” I said, as I looked at them. “Yes,” said Tom laughing, “Mrs. Rosnosky taught you to know platinum when you see it. Just look through this.” He held the tube before us, and the same magic bending of the lines showed as we gazed. The tube was filled with the gas that I had seen in the shade above.