Page:Popular Science Monthly Volume 1.djvu/266

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254
THE POPULAR SCIENCE MONTHLY.

MAGNETIC VARIATIONS.

The last word about solar influence is uttered by Carl Hornstein, of Prague, who, summing up the results of an immense number of observations, says that the variations of each of the three elements of terrestrial magnetic force, declination, inclination, and horizontal intensity, have a period of about 26⅓ days. This periodicity can hardly be explained, except by the influence of the sun.

 

COLD IN GERMINATION.

The cold of winter is said by M. Duclaux, of the Paris Academy of Sciences, to be necessary for the germination of certain vegetable grains, and for hatching the eggs of the silk-worm. His researches in this matter he proposes to continue and to extend, so that the effects of cold may be ascertained to the greatest possible degree of exactitude.

 


NOTES.

A remarkable case of reproduction of the elbow-joint after resection is given by the British Medical Journal. The subject was a weakly girl, aged 13, whose elbow had become fixed in a faulty position, after inflammation. On account of this, and of disease of the bone, resection or removal of the joint was performed. The piece of bone removed was one and a third inch long in front, and two and a half inches behind; the articular portions of the bones of both arm and forearm being thus taken away. The child recovered, with power of moving the elbow between the angles of 60 and 113 degrees; rotation, however, was impossible. Two and a half years after the operation, the child died, and, on examination, a new elbow-joint was found, having its articular surfaces covered with cartilage, and provided with a synovial membrane.

The Engineer says that the oxyhydric light has not proved a success in Paris, and it has been discontinued in the public lamps on the Boulevard des Italiens. It is not generally known that a carburating apparatus is always employed in conjunction with oxygen, which adds to the complication of the apparatus as well as the cost of the light. There are but few, remarks Le Gaz, who will consent to have installed in their houses two meters, two regulators, a carburator, and two distinct systems of pipes. For this reason alone the system was certain to fail, even if the alleged economy were proved which has never been the case.

A simple mode of distinguishing with certainty between apparent and real death is given by Dr. Ars-Drouet, of the Paris Academy of Medicine. It consists in fastening a bandage, handkerchief, or cravat, etc., around the forearm, just below the elbow, or around the leg below the knee. If the patient still lives, the subcutaneous veins become inflated, swollen, and bluish under the skin; but, if life is extinct, there will be no change in the appearance of these veins.

From a statement made by Dr. Günther, in the January number of the Magazine of Natural History, it would appeal that the national collection which in the year 1858 contained 480 species of snakes, represented by 3,990 examples, possesses now 920 species, represented by 5,500 examples. The number of typical specimens is 366, the total number of species of snakes known at present being calculated at about 1,100.

The perfect fossil skeleton of a man has just been discovered in a cavern near Meudon, France, by Dr. Rivière, who sends a communication on the subject to the French Geological Society. The skeleton was in an inclined position, and in the attitude of repose: the legs were partially bent, and the one rested on the other. A necklace made of shells and perforated teeth was found upon it.

Experiments with petroleum as a fuel in the puddling-furnace are said to have been attended with great success in France. The experiments were made under many varying conditions, and were conducted by practical and reliable men. It is asserted that, for convenience, efficiency, and, above all, for the superior quality of iron produced, there is nothing that equals petroleum in this manufacture.

In a paper read before the Iron and Steel Institute of England, Mr. J. Head states that, while there is as much heating-power in a pound of average coal as is necessary to produce 17 pounds of puddled bar-iron, there are few furnaces where more than one pound of iron is brought out to one pound of coal consumed.

If a sailing-ship be provided with a screw-propeller, the latter will revolve when the ship makes way; and it is proposed to apply the power thus obtained to operating a magnetic apparatus, which would furnish a far brighter signal-light than any oil-lamp.