According to the observations of a writer in Land and Water, the time required for fish-eggs to hatch varies greatly with different seasons. He states that in 1869 ova from the trout hatched in 55 days, in 1870 they were 92 days hatching, in 1871 95 days, and in 1872 they hatched in 82 days. With the exception of temperature, the conditions were identical in the different years. The first year there was no frost, and the ova were in a house with a glass roof, and consequently at a high temperature. The second and third years there were long frosts after the eggs were placed in the boxes, and this year there was also some frost.
Catoptric lamps, or lamps provided with reflectors, are being introduced in London for lighting the streets. The reflectors are so placed in the top of the lamp that those portions of the light ordinarily passing skyward are made to illuminate the foot-ways. The light is evenly distributed; and from the same jet, as shown by the photometer, three times as much illuminating power is obtained as by the old-fashioned lamp.
Prof. Pepper, of ghostly fame, is giving in London a popular scientific entertainment, followed by a lecture on "spiritualism." The professor announces himself as ready to give all the "manifestations" usual at "spirit séances". He "tips" the tables, and "scratches" the same, with all the airy grace of a disembodied sprite. The "hand of glory" is to be seen at his entertainments, and a violin is made to float in the air. Mr. Pepper has not yet perfected his arrangements for "floating" himself à la Home, but that feat is "on the bills," and will be performed in a few days. The means by which he performs these marvels he keeps secret at present, but promises to publish them after a few months.
The use of rubber plates and rings, for making connections between steam and other pipes, is often attended with much annoyance, owing to the leakage of the joints. This may be prevented by employing a cement prepared by dissolving shellac in ammonia. The pulverized gum-shellac is soaked in ten times its weight of strong ammonia, when a slimy mass is obtained, which in three or four weeks will become liquid without the use of hot water. This fastens well both to the rubber and to the metal or wood, and becomes, by volatilization of the ammonia, hard and impermeable to either gases or fluids.
Coloring Matter in Fungi.—Mr. H. C. Sorby has determined the existence of at least 30 distinct coloring substances in fungi. The majority contain at least two, and many of them several, different kinds. Twenty of these have such well-marked optical qualities that they could be recognized without difficulty in other plants, but only one of them, a fine orange-color, is known to exist in any plant not a fungus. As far as Mr. Sorby's observations extend, there is little or no specific agreement between the substances found in fungi and those met with in algae and lichens, though the two latter orders are closely related in this respect.—Science Gossip.
Prof. Herman, in a paper published in Pflüger's Archiv, states that living muscle offers very much greater resistance to an electric current passing in a direction across the fibres, than to one transmitted along them, the average difference being as seven to one. In muscles that have passed into the condition of rigor mortis (stiffening of death), this difference almost entirely disappears. A similar difference in the amount of resistance offered to the passage of an electric current is observed in the case of the nerves, though the ratio is somewhat less, being about five to one.
New Fossil Fish.—Sir Philip Egerton has just described a new genus of fossil fish from the lias of Lyme Regis, to which he has given the name Prognathodus. Dr. Günther is of opinion that in its dentition it establishes an additional piece of evidence in favor of the connection between the Ganoid and Chimaeroid forms.
The liability of glued articles to come to pieces when exposed to the action of water, especially hot water, is familiar to every one. By adding to the water, with which the glue is mixed when required for use, a small quantity of bichromate of potash, and afterward exposing the part to which it is applied to light, the glue is rendered insoluble, and articles fastened with it resist the action of water. The proportion of bichromate of potash to be taken must be determined by experiment, but for most purposes one-fiftieth of the amount of glue employed will be sufficient.
The Emperor William, who, during the late war, became noted for his disinterested generosity in ascribing the numerous German successes to the favoring hand of Providence, is now furnishing more substantial, and if possible more high-sounding tokens of his regard, in the shape of church-bells, which the Builder tells us are being cast in great numbers from the cannon captured from the French, for use in German churches.
Certain minerals, such as rose-colored silex, native arsenic, and red arsenic, undergo a change when the solar ray falls upon them. The last-named mineral is reduced to a powder, and its red crystals change to orange-color. M. Jannetay, of the French Geological Society, has studied the action of the various luminous rays in this regard, and finds that the red rays alone do not alter the minerals in question.
M. Louvel proposes to store grain in air-tight granaries from which the air may be partially exhausted by means of a powerful air-pump. He claims that in this way grain may be much better preserved from decay, and the ravages of insects are effectually stopped. The cost of such a granary capable of holding 300 bushels of wheat would be, in France, about 150 dollars.
The subcutaneous injection of morphia in cholera has been satisfactorily tried by Dr. Augustus Werry, of Constantinople. In from 15 to 20 minutes after the injection, the patients fell into a calm sleep, and awoke in two or three hours bathed in a warm perspiration, and saying that they were "well again." Dr. Werry treated in this way 22 cases of cholera, presenting almost every phase of the disease, violent vomiting and cramps, dyspnœa, reduced temperature of the body, diarrhoea, weakened circulation, etc., and always with beneficial results. The dose of morphia injected varied from one-twelfth to one-half of a grain.
According to a correspondent in Harper's Weekly, the horned frog of our Western plains is ovoviviparous, that is, producing eggs that are hatched before leaving the mother's body, the young being brought forth alive. He states that, while crossing the plains some years ago, he carried with him several of these animals, and, on examining them one night, found that 24 young ones had suddenly made their appearance, each one about the size of a dime, and all very lively.
A certain M. Donac has recently laid before the French Academy of Sciences a project for liquefying dead bodies and transforming them into a syrup without color or smell. According to his calculations, a moderate-sized man could be got into six bottles. The size of each bottle is not stated, but the Paris Journal appears charmed with the idea, and exclaims, "What an opening for the exercise of filial piety!"—Lancet.
One of the ostriches in the Zoological Gardens, London, recently dying, an examination of the stomach showed the cause of death to be copper-poisoning, that organ containing a number of copper coins, and pieces of coins in a much-worn state.
The death is announced of Professor von Mohl, the eminent botanist, who expired on the 1st of April last, at Tübingen, aged sixty-seven. At thirty years of age he was appointed Professor of Botany and Director of the Botanic Garden, at Tübingen, retaining the position until his death. Since 1843 he has been editor of the Botanische Zeitung, and for the last thirty-five years was one of the foreign members of the Linnæan Society. Giving special attention to the study of vegetable anatomy and physiology, he has written extensively on these subjects; his works contain the result of much original observation.
Nature records the occurrence of seven earthquakes in January last. Two were in Central and one in South America, three in India, and one in Asia Minor.