Page:Popular Science Monthly Volume 25.djvu/879

Rh abundance in deep-sea deposits at distances from land that preclude the supposition of their having originated in inhabited countries, and their form and character are essentially different from those of bodies collected near manufacturing centers, with which the attempt has been made to associate them. After describing some of these spherules, with graphic illustrations of their structure and composition, the authors express the belief that they have presented enough evidence to show that in their essential characters the spherules are related to the chondres of meteorites, and are formed in the same manner.

Manganese in Plants.—M. E. Maumené has found manganese in wines and in a considerable number of vegetable and animal products in which it had hardly been supposed to be present; and now announces, as the result of his latest investigations, that he has detected it in a great many plants. Wheat contains not less than from to  metallic manganese, and rye, barley, rice, and buckwheat have also yielded considerable quantities of it. A little of it may be found in the potato, and more in the beet, the carrot, beans, peas, asparagus (principally in the green part), sorrel, wild chicory, lettuce, parsley, and in many fruits. It occurs in large proportions in cacao and the coffees, and in tea there are five grains of the metal to one kilogramme of the leaves. Tobacco is quite rich in it, as are also a variety of other plants, including some forage and some medicinal plants. The human system refuses to absorb it, and whatever of it may be introduced with the vegetable food in which it is present is eliminated with the fecal matter.

Gutta-Percha.—The earliest known mention of gutta-percha is by John Tradescant, who, in the catalogue of his "Rarities," preserved at South Lambeth (1656), mentions "plyable mazer wood," which, "being warmed in water, will work to any form." The earliest introduction of the gum to the commercial world is due to Dr. William Montgomerie, of the East India Company's service, who experimented upon it at Singapore, in 1822, and recommended it to the Medical Board of Calcutta in 1842 as a substance useful in the making of surgical splints. The name gutta is a Malay word, signifying gum, or juice. The gum is derived from the middle layer of the bark of a number of trees of the order Sapotaceæ to which order also belong the sapodilla-plum and the vegetable-butter trees. The principal source is the Dichopsis gutta, a plant which was described by Sir W. J. Hooker, in 1847, as Isonandra gutia. Dr. De Voiese, of the Dutch Government service, names eighteen species that yield the gum. The Dichopsis gutta is found in the Malay Peninsula, Sumatra, Borneo, and throughout the Malayan Archipelago generally. It grows to a height of from sixty to eighty feet, with a diameter of from two to five feet. The leaves are inversely egg-shaped (oblong in one variety) and entire, pale-green on the upper side, and covered beneath with a reddish, shining down. The flowers are arranged in clusters of three or four in the axils of the leaves. The fruit is a small oval berry. The gutta, as it flows from the tree, is of a grayish color, at times somewhat roseate in hue. When cast or rolled it assumes a fibrous structure, and acquires a tenacity in a determinate direction. At a temperature of from 32° to 77° Fahr., it has as much tenacity as thick leather, but is not at all elastic, and is less flexible than leather. In water, toward 120° Fahr., it softens and becomes doughy, although still tough; at from 145° to 150° Fahr. it becomes soft and pliant, assuming the elasticity of caoutchouc, but becomes again hard and rigid on cooling. It is highly inflammable, burning with a bright flame, and has marked electric properties.

Courtesy and Sagacity of the Duck.—A correspondent of the London "Spectator" extols the courtesy and sagacity of the duck. In illustration of the former trait, he tells of a "solitary, little, old bantam hen" he had among some fifty or sixty head of ducks and fowls, which became blind, or nearly so, and had to "sulk" in the dark to escape the persecutions of her mates. "Here," he says, "she might, perhaps, have starved, but for the constant and sympathetic attentions of a duck. Twice daily, every day so long as the poor bantam lived, some three weeks, this good Samaritan, in