Page:Popular Science Monthly Volume 37.djvu/150

140 the opinion of the author, the principal cause in hastening geyser-action. It tends to cause the steam to be retained within the basin, and, when the temperature stands at or above the boiling-point, explosive liberation must follow. All alkaline solutions exhibit, by reason of this viscosity, a tendency to bump and boil irregularly. Viscosity in the hot springs must also tend to the formation of bubbles and foam when the steam rises to the surface, and this in turn aids to bring about the explosive action, followed by a relief of pressure, and thus to hasten the final and more powerful display. The practice of casting in soap is regarded as detrimental to the preservation of the geysers, and as a proper object of restriction.

The Nature of Poisoned Arrows.—The word poison, as applied to the poisoned arrows used in the Solomon Islands, Santa Cruz, the Banks Islands, and the New Hebrides, should be understood, according to the Rev. Dr. R. H. Codington, in a peculiar sense. The practice of administering poison in food was common among the natives, but it was doubtful whether what was used had much power of doing harm. The deadly effect was expected to follow from the incantations with which the poison was prepared. In the same way the deadly quality of the poisoned arrows was never thought by the natives to be due to poison in our sense of the word, though what was used might be, and was meant to be, injurious and active in inflaming the wound. It was the supernatural power that belonged to the human bone of which the arrow-head was made on which they chiefly relied, and with that the magical power of the incantations with which it was fastened to the shaft. The bone of any dead man will give efficacy in the native belief to the arrow, because any ghost may have power to work on the wounded man; but the bone of one who was powerful when alive is more valued. In Lepers' Island, a young man, out of affection for his dead brother, took up his bones and made them into arrows. He carried these about him, and did not speak of himself as "I," but as "we two"—his brother and himself—and he was much feared; all the supernatural power of the dead brother was with the living. Although it is the human bone that gives the deadly quality to the arrow, the bone must be prepared with certain incantations which add supernatural power. The poison is an addition to the power of the bone. The native did not much consider, if at all, the natural power to hurt, of either bone or poison. A dead man's bone made the wound, the power of the ghost was brought by incantation to the arrow, and therefore the wounded man would die. Euphorbia-juice is hot and inflaming; it is smeared on the bone with an incantation which calls in the power of a dead man's ghost; when the wound is given, the ghost will make it inflame. The cure of the wounded man is conducted on the same principle. If the arrow-head, or a part of it, can be recovered, it is kept in a damp place or on cool leaves; the inflammation of the wound is little, or subsides. Shells are kept rattling over the house where the man lives, to keep off the hostile ghost. In the same way the enemy who has inflicted the wound, and his friends, will drink hot and burning juices, and chew irritating leaves; pungent and bitter herbs will be burned to make an irritating smoke, and will be tied upon the bow that sent the arrow; the arrow-head, if recovered, will be put into the fire. The bow will be kept near the fire, and its string kept taut and occasionally pulled, to bring on tension of the nerves and the spasms of tetanus. Prof. Victor Horsley has suggested that the value of the human bone tipping the arrow was first made evident by the employment of a bone from a corpse recently dead, in the decomposing tissues of which the septiæemic virus would consequently be flourishing.

The Mesozoie Atlantic Coast Region.—In his address before the Geological Section of the American Association, Prof. Charles E. White, defining the Mesozoic formations of North America, said that the rocks of the Triassic age are found from Prince Edward Island to the Carolinas. They rest on formations, from the Archæan to the Carboniferous, inclusive. Very few invertebrate fossils have been found in the Trias of the Atlantic coast region, and these are of little value for indicating the age of the strata that contained them. Intermediate between the Triassic beds and the undisputed Cretaceous deposits of this region is a series of