Page:Popular Science Monthly Volume 38.djvu/587

Rh it ferment. After a time it is dug up and eaten; but the smell is rather strong at first. Fiji is a commonwealth in the proper sense of the term, all articles being public property. No native lives by trade, and they seem to have no idea of the principles of commerce. They are industrious, and adepts in pottery and wood-work, although their implements are for the most part crude. The native drum, formerly used to sound the war alarm, is now employed to summon people to church, which they all attend.

Ocean Transportation of Plant Species.—Experiments performed by Dr. Guppy at the Keeling Islands, which are six or seven hundred miles from the nearest large land, show that certain kinds of seeds will germinate freely after being thirty, forty, or fifty days in sea-water. During this time they may be conveyed, on a drift current of only one knot an hour, a distance of from one thousand to twelve hundred miles. Some seeds that do not readily float, or float only for short periods, are conveyed hither and thither in a variety of ways—as in the cavities of pumice-stone, and in the crevices of drift-wood. Such seeds as germinate have difficulties in establishing themselves, the most formidable of which are caused by the crabs, which eat the green sprouts as soon as they appear. If the plants escape the crabs in their earliest infancy, they are safe. An evidence of the tenacity of life under unfavorable conditions is afforded by the fact that despite clearing and cultivation, and the introduction of foreign enemies, no species of plant ever known to grow wild on the little islands has become quite extinct.

The Wise Use of Medals.—More discrimination in awarding medals by learned societies is recommended by Prof. W. M. Williams. "Looking critically," he says, "at the awards that have been made during the present generation, it is difficult to find a case in which the honor has not been fairly earned; but still, I think, they have not been as beneficially awarded as they might have been, nor in the manner generally desired by their founders. Most of them were intended as a stimulant, encouragement, and help to scientific workers. Such a medal would be all these to a poor or young or obscure worker, but is none of them to a man whose reputation is established, whose scientific eminence is already attained, and who is already quite sufficiently official." A case in point is that of J. A. R. Newlands, whose duly published discovery in 1864 and 1865 of the periodic law of the chemical elements was not noticed, while the Royal Society's Davy medal for the same discovery was given four or five years afterward to the "official" chemists Mendeleef and Lothar Meyer. But at length, in November last, Newlands received the medal which he had earned previous to either of the other chemists.

Leonardo da Vinci's Theory of Fossils.—M. Charles Revaisson is publishing phototypic fac-similes of the manuscripts of Leonardo da Vinci. It seems that nothing which constituted the scientific domain of mankind in the sixteenth century was strange to that illustrious artist. We give here his theory of the formation of fossils: "Of animals which have bones on the outside, such as shell-fish, snails, and oysters, of innumerable species.—When the floods of turbid rivers discharge fine mud on the animals living in the adjoining waters of the seashore, the animals remain pressed in the mud, and, being overwhelmed by its weight, necessarily die for want of the creatures on which they are accustomed to feed. The sea receding in time, this mud, the salt water having run off from it, becomes changed into stone, and the shells are filled with sand instead of the animals that have decayed from within them. Thus, in the midst of the transformation of all the surrounding mud into stone, that also which remained within the shells becomes joined by means of a slight opening of the shells with the other mud; so that all the shells are inclosed within the stone—that is, the stone that includes them and that which they contain. These shells are found in many places; and nearly all the petrified mollusks in the rocks of the mountains still have their natural shells—particularly those which had grown old enough to be preserved by their hardness; and the young, being already for the most part reduced to lime, had been penetrated by the viscous and petrifiable humor.