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THE POPULAR SCIENCE MONTHLY.

pressed into the form of bricks, when it becomes an excellent fuel.

The material used for capping champagne, beer, and mineral-water bottles, supposed to be simply tin-foil, turns out on examination to consist almost entirely of lead. Dr. Wittstein, after analyzing a great many of these capsules, states that the proportion of tin in their composition varies from one to ten per cent., all the rest being lead; and that the prevalent habit of closing the top of the bottle with the cap after the cork has once been drawn is a dangerous one, as the acid contents of the bottles even in minute quantities, in contact with the cap at the mouth of the bottle will rapidly dissolve the lead, and thus give rise to a poisonous solution.

One of the most distressing, because rarely remedial forms of chronic mania, says the London Lancet, is that produced by the mental shock of fire. The patient wears a peculiar aspect, in which suspicion is one element, and a settled look of panic another. Photographs of such inmates of asylums are remarkably uniform in their representation of this expression. The great fire at Chicago has produced a large number of lunatics, no fewer than 250 sufferers from it having been adjudged insane by the courts of Illinois. Considering the privations, however, to which the houseless victims of that conflagration were in many cases exposed, other causes than fire-panic may be credited with a share of the result.

According to Van Beneden, as quoted in the American Naturalist, an excellent method of preparing for preservation and study such jelly-like and perishable organisms as medusæ, ctenophora, noctilucæ, etc., is to immerse them for from fifteen to twenty-five minutes, when fresh, in a weak solution of osmic acid, when, after washing several times in water, they may be kept, for weeks or months without impairment, in alcohol. The acid colors a portion of the tissues brown, but this rather facilitates than hinders study, as it brings into view certain structures that are otherwise less clearly visible. The agent also hardens the substance of the animal, so that it may be handled without danger of disorganization, and readily cut into sections if desired.

Fever is the most prolific cause of death in India, and, in ordinary years, carries off many more victims than all other diseases together. The returns, exclusive of Bengal and the northwest provinces and Burmah, give upward of 900,000 deaths from fever in 1871, and the total number in all India cannot be far short of 1,500,000. At least half of these lives might be saved by putting quinine in every native druggist's shop at one rupee per ounce.

The United States Light-house Board have under charge 179 sea and lake coast lights, 394 river and harbor lights, 22 light-ships, and 33 fog-signals, that are operated by steam or hot-air engines.

The Gazette des Campagnes recommends dipping the end of plant-slips in collodion before setting them out. The collodion should contain twice as much cotton as the ordinary material used in photography. Let the first coat dry, and then dip again. After planting the slip, the development of the roots will take place very promptly. The method is said to be particularly efficacious with woody slips, geraniums, fuchsias, and similar plants.

Chloride of cobalt, sometimes used as the basis of a sympathetic ink, is, according to Siegen, a powerful poison. A grain killed a frog in half an hour. Four and a half grains killed a strong rabbit in three hours. The poison acts directly upon the muscles of the heart. Nitrate of cobalt is equally poisonous, and acts in a similar way.

Camphor-wood promises to become, at no distant day, an important article of commerce. It grows freely in tropical countries, without cultivation. The tree attains large proportions, being sometimes found fifteen feet and upward in diameter, and of proportionate height. It is very valuable for carpenter's work, being light, durable, and not liable to injury from insects. Its aromatic perfume is well known. The wood is strong and very durable, and is especially serviceable in ship-building. Camphorwood piles have been known to remain in a good state of preservation over a hundred years.

Ixtle-fibre, which grows abundantly on the southern shores of the Gulf of Mexico, is remarkable for its lustre, strength, and flexibility. Within the thin envelope which forms the leaf, there is a perfect skein of thread of extraordinary tenacity, length, and fineness. The outer covering can be easily removed by a chemical process, and the whole fibre made available without further expense. The plant, it is said, can be brought to New York for less than fifty dollars per ton.

In a French industrial establishment, employing 630 men, chiefly vegetarians, the sick fund was constantly in debt. The director of the establishment took measures for the introduction of butcher's meat into the food of the men, and the effect was such that the average loss of time per man, on account of illness or fatigue, was reduced from fifteen to three days per annum. Thus the animal food saved twelve days' work a year per man.