But Jean, left alone, was the prey of thoughts less simple. As she watched the hydrogen exude from the zinc, which contained enough carbon or iron to start that flow, she wondered first if the whole bar might not be made of hydrogen. Then she recalled the terrific explosive power of those tiny bubbles. A few fragments of commercial zinc left by accident in the boiler of a steamer had been known, when the hot water attacked it, to give off hydrogen and blow the stokers into shreds. Zinc, however, was tame as compared with its beautiful cousin, quicksilver. Mercury fulminate was the very prince of all the devils that produce explosion. She thought she understood now the elegant process which had destroyed Horatio. A bomb containing finely divided aluminum and iron oxide, and a bit of burning magnesium ribbon, came dropping down out of heaven. On the way the oxygen of the iron united with the aluminum and made a molten mass. This struck the exquisitely sensitive mercury fulminate in the shells, and this in turn exploded the stores of horror in the whole dump of ammunition. That was the sort of thing that chemists were guilty of. Their brains were a thousand years ahead of their passions. They were savages with the intellect of angels. Who knew but that her own lover, in some fit of anger, might not be capable of just such horrors? She would not marry him! But what force can prevent the human eye from seeing and the human mind from inquiring? As the mercury continued to fall and the river began again to sheath itself in blue crystal, she simply could not help wondering why the lovely stuff in the thermometer was so different from gold. Quicksilver was just a trifle heavier than gold and yet a liquid! Gold would stand any amount of pounding, and mercury could not be pounded at all. The marvel of it wearied her, and she turned aside from her studies to prepare for Christmas. She hungered for the sight of little children. She would ask the grange to bring all of them on sleds to her house for a party, and she would make them toys with her own hands. It must be confessed that she was happier doing this than in trying to think out mercury. To fashion a hazel nut into the brown and black head of an Indian baby, or to split cedar into fairy supports for the wings of a toy air-plane—this was nearer her intellectual size. December sped along, and her father cut a superb spruce for a Christmas tree. She festooned it with popcorn and wished that she had just a few of the glittering baubles which gleam among the branches of such trees in town. Then a day or two before Christmas Ojeeg brought her, along with a present from his son, a box containing a whole wilderness of ornaments, together with a letter which ran as follows: Dearest Jean Winifred: