Page:Popular Science Monthly Volume 36.djvu/296

284 the seeds to soak; it only shortens the time the seeds have afterward to remain in the soil. The character of the soil may influence the results. Light, when it has any influence and it has great influence with some species—has a retarding effect. The weight of the seed is often a tolerably accurate measure of its viability. As a rule, heavy seeds germinate better than light ones of the same sample. When variability was perceived with reference to color, the stronger sproutings usually occurred in the darker-colored seeds. The latitude in which seeds are grown may determine their behavior in germination—northern-grown seeds seeming to germinate more quickly than southern-grown. More than one test is needed to be decisive respecting any sample of seeds. There appear, from the testings reported, to be no pernicious adulteration of garden seeds in this country, and no hurtful impurities.

Tapioca.—The manihot, or tapioca plant, was originally a native of tropical South America, but is now largely cultivated throughout all tropical countries. It is a small, shrubby plant, growing from four to eight feet high; and becomes suitable for use in from sixteen to eighteen months after the young plants are established. Besides the well-known wholesome food, the root abounds in a peculiar poisonous juice, which is said to be analogous to hydrocyanic acid; but this substance being volatile and easily destroyed by fermentation, no difficulty is met in procuring the food-product free from it. The pulp obtained from the roots is washed in cold water, after which, upon resting, the starch subsides. The water is then drawn off and the starch is heated, when pearl tapioca is obtained. In preparing the cassava meal, the roots having been prepared, are baked on an iron plate. Thus prepared, the meal swells considerably in water or broth, and is called cerraque. If, instead of drying the grated pulp, it is spread upon a hot iron plate, the starch and mucilage, by mixing together, consolidate the pulp and form a biscuit, called cassava bread, which is a very important and nutritious food. The resultant of the mastication of these cakes, upon fermentation, produces an agreeable but intoxicating drink.

The Island of Paros and its Marbles.—The Island of Paros, according to Mr. R. Swan's description in the British Association, is eleven miles long and eight miles broad at its widest part, with a mountainous interior rising to a height of twenty-five hundred and thirty feet, and a broad belt of nearly level land round the coast. The southern part of the island consists chiefly of crystalline limestone, of undefined age but probably Cretaceous. The finest statuary marble, or lychnitis, varies from five to fifteen feet in thickness at the quarries of St. Minas, and occurs in a bed of coarse-grained white marble with bluish-black veins. The coarse marble becomes dark in color near the lychnitis, both above and below it, and thus the layer of statuary marble is distinctly marked off. The dark color is due to traces of binoxide of manganese and magnetic oxide of iron. The rocks are much disturbed and folded, and often clip at high angles. The ancients avoided the marble lying near the axis of elevation, which was of inferior quality to the other parts. A Greek company, formed a few years ago to work the quarries, attacked the rock here, where it could be got at least expense, and so discredited the marble in the market that it went down, after one hundred and sixty thousand pounds had been spent in getting the quarry ready. There is a good deal of excellent colored marble on the island, but, not having been used by the ancient Greeks, is not much known.

A Classification of Incendiaries.—Dr. J. A. Fowler, of Philadelphia, has made a classification of more than twenty different kinds of incendiaries, or motives to incendiarism. They are 1, the incendiary policyholder; 2, the incendiary for gain or advantage other than insurance; 3, the revengeful incendiary; 4, the discharged hand; 5, the malicious servant; 6, the rioter; V, the tramp; 8, the thief (for concealment of theft); 9, the thief (for opportunity for theft); 10, the murderer (for concealment of crime); 11, the incendiary for murder; 12, the mischievous small boy (or girl); 13, the contriver for incendiary reward; 14, the fire-bug, or fire conspirator (terrorizing by fire); 15, incendiarism from momentary rage; 16, the drunken incendiary; 17,