Page:Popular Science Monthly Volume 17.djvu/881

Rh burst forth in bunches, slowly uncoiling themselves. They were white, stiff, and wire-like, and not at all stained with blood. The large blood-vessels of the lungs were filled densely, and large filariæ were withdrawn with some difficulty even from the small ones. The worms lived in water about twenty-four hours.

Production of Artificial Diamonds.—Mr. Hannay lately gave an account to the Royal Society of his experiments in producing artificial diamonds. As far back as the fall of 1879, he was searching for a solvent of the alkali metals, and tried many experiments with different liquids and gases, with the invariable result that, when the solvent reached the permanently gaseous state, chemical action ensued. A number of experiments were made with sodium, potassium, and lithium, and the hydrocarbons, but the metals almost invariably combined with the hydrogen, setting the carbon free. A series of experiments made with sodium and paraffine-spirit gave a deposit of very hard scales of carbon. This was the reaction upon which the experiments for obtaining crystalline carbon were built. From his experiments in solution, Mr. Hannay concluded that the solvent power of water was determined by two conditions: first, temperature, or molecular vis viva; and, second, closeness of the molecules on pressure, which seems to give penetrative power. It should follow, then, that, if one body has a solvent action upon another without acting upon it chemically, such solvent action may be indefinitely increased by increasing the temperature and pressure of the solvent. Out of more than eighty experiments which Mr. Hannay made for producing crystallized carbon, only three were attended by results of a satisfactory nature. The first experiments were made with sodium and paraffine-spirit, in tubes of hydraulic iron, twenty inches long, an inch thick, and of a half-inch bore, three parts filled. The tubes, fitted with screwed plugs, nearly all leaked, and had to be welded up. Then one exploded before it became visibly red, another showed a deposit of scaly carbon, and a third gave out a strong jet of gas when opened, while the iron appeared to have been converted to steel. Concluding that diamonds were not likely to be obtained by that means, Mr. Hannay returned to the idea of dissolving carbon in a gaseous menstruum. A distillation from bone-oil containing nitrogenous bases seemed to him the most likely substance to yield the solvent. It was placed in a strong tube with charcoal, and heated for fourteen hours. The gas rushed out with force on opening the tube, and a few bright particles of carbon appeared, differing but little, however, from particles of wood-charcoal. Another experiment was made with lithium and a mixture of highly rectified bone-oil and paraffine-spirit, placed in a tube twenty inches by four inches, with a bore of half an inch. This was heated for fourteen hours, then cooled slowly. On opening it, after the outrush of gas a little liquid was found, and at the upper end of the tube as it lay in the furnace, a hard, smooth mass, which was removed with a chisel. Some hard particles were found in pulverizing this mass, which, on examination, proved to be transparent crystals of carbon, or diamonds. New experiments were made with other alkali metals, paraffine-spirit, and bone-oil, but they yielded nothing except the scaly carbon. Even the lithium did not act in the same manner as before. This metal having, however, given the best results, Mr. Hannay determined to use it in his further experiments, but was troubled by frequent disasters and explosions, although he again got, in one of the trials, a small quantity of carbon crystals. A curious fact that has been brought out by the examination of the crystallized carbon that was obtained is that nitrogen was present in chemical combination with the carbon. Mr. Hannay is inclined, therefore, to believe that his diamonds were formed by the decomposition of a nitrogenous body, and not by the decomposition of the hydrocarbon. The diamonds, moreover, were not found when nitrogen was absent; but the successful experiments are still too few, and the evidence too vague, to justify drawing any conclusions on this subject.

The Nile and its Ancient Channels.—M. Delamotte, who has made himself well acquainted with the geology and geography of Egypt, has published the opinion that, besides the Nile, that country was watered