He called Marese to look over his drawings, and to witness his experiments with the acid. Marese was enchanted; his confidence in Theodore’s scientific resources was confirmed. There was, however, one question he asked—Was the gas so strong and so poisonous that the small quantity confined in a case three feet square would destroy a whole ship’s company? Would not the gas escape, rise up, and dissipate itself through the port-holes, up the hatchways, and be further weakened by the breezes that blew and caused draught in various places between decks? These ocean steamers were very roomy. Theodore was delighted to have an opportunity of explaining the properties and nature of the vapour to his friend. The peculiarity of this gas was that, although an invisible fluid, it was extremely heavy—it was heavier far than atmospheric air. He easily proved that a gas might be heavier than air by a well-known experiment with a vapour (not the one to be used in this case) which he poured out of a glass phial over a candle. The invisible gas descended and extinguished the candle; There was not the slightest chance of the poison-vapour escaping quickly through ports or up hatchways. It would, as it were, cling to the vessel. The pressure inside the case would cause it to issue rapidly from the aperture eaten out by the acid. It would then diffuse itself laterally, and gradually penetrate into every crevice and corner of the ship. The effect would be that one by one every person on board would inhale it, and in an instant, let the quantity breathed be never so small, down he would drop, or grow rigid as he sat—unconscious was the word Theodore used as an euphemism for death. He did not mention another effect it would have, lest the horror of it should cause even Marese to falter. Theodore traced out the probable course of events on board the fated vessel. First, the persons working or living in the cabins and places nearest the case would feel the effect and succumb. Then there would be alarm and excitement—others would rush to the spot, and they would immediately fall, just as the birds and beast did who entered those fatal caves abroad. One man on board, perhaps, might detect the cause—the surgeon, or any doctor who chanced to be a passenger—and might cry out to man the boats and escape; but who, in the hurry and excitement, would heed him?—he would not have time to escape himself, much less to explain the danger to others. It was doubtful whether even so much as a signal of distress would be hoisted. The crew, the officers, the passengers would be so completely puzzled, so utterly at their wit’s end, that no course would suggest itself to them before it was too late.