SCIENCE NOTES.

Otago Witness, Issue 2425, 5 September 1900, Page 62

SCIENCE NOTES.

— The testimony of witnesses to drownings nn various occasions needs to be cpllected before it can be stated as the xisual fact that there is a rising to the surface three times. The human body in life, or with the lungs inflated, naturally floats, as every one kaows who has learned to swim, or even to keep his mouth above the surface of the water ; and one to whom this discovery has come can float faca up without moving hand or foot. But how soon a frightened victim of accident can gulp enough water to drive the air out of his lung 3is another question. Undoubtedly, it has become a tradition everywhere that the drowning rise three times, and every reporter of an incident or every story-tellar .thinks he must give spice to his tale by talking of "rising the third and last time," at which crisis the rescuer is always supposed to seize and save the -victim. — H. Retzbew, in Popular Science News.

— The salt wells of Sze-chuen are one of the sights, as well as one of the important inckistries, of that great province in China. During high water in summer and autumn (says the Engineering and Mining Journal) these salt springs are submerged, but when the river subsides P.' mushroom town of straw shanties is run , up, .the evaporating pans are get in mud furnaces, and the work goes continuously on till next high water again submerges the springs and drives the salt boilers pff. The. salt is a hard, dirty-looking mass when taken from the pans, but the Chinere are proml of tho product of their wells, and affirm that its power of salting is much greater than the white-looking article of foreign commerce.

— A new material for the use of builders {ias recently been introduced in Norway. It s a paper, or pasteboard, which with aßphalturn is pressed into a Eolid plate, forming a Very serviceable material for covering walls Rnd ceilings. It is damp-proof and is a Xion-conduclor of heat, so that it will keep p, room warm and comfortable, while at the *ame time it deadens noise and prevents the

harbouring of vermin. It io' solid, but can be readily bent so as to conform to all the* angles and projections of a wall without breaking oi_ cracking. It is very suitable for panelling, and is even cheaper than the thin boards usually employed for this purpose. It is without odoar, and will never decay. It is 'fair to state. that a material with several of these advantages has long been known in England under the name of Willesden paper. This, too, is waterproof, is mads in several thicknesses, and can be treated with paint or other surface preparation without difficulty. It takes its name from the place where the factory for its production is situated.

— Count yon Zeppelin is now constructing, on Lake Constance, another balloon, which is to be "navigable." The balloon is to be 416 ft in length and 38ft in diameter, divided into 17 compartments, and supported on an aluminium framework. It is to carry two cars and motors, and to be propelled by screws placed in pairs at the side of the balloon and geared to the drifting shaft by two diagonal shafts. In the preliminary experiments on Lake Constance, the propellers, which are to drive the balloon .through the air, drove a launch through the water at from sis to nine miles an hour. • The fuel is benzine, and it is calculated that the balloon will carry sufficient fuel to perform a journey of 180 miles.

— In a recent communication to the French Academy of Medicine, M. L. Dutremblay advocates the treatment of sea-sickness by inhalation of pure oxygen under pressure. "The first attsmpbs in this direction," says La Nature, "were made sv.ccessfully by Dr Dubois, Professor in the Faculty of Sciences at Lyons, who recognised as the principal cause of seasickness the incomplete ventilation of the lung, with consequent increase of the residual air and imperfect respiratory action. Dv tremblay, aided by Dr Perdriolat, physician ,to the Compagaie Generale Transatlantiqxie, took up and completed these experiments on numerous persons at sea, According to him, the sudden and violent displacements of the visceral, mass and the contraction of the diaphragm act as principal causes, and bringabout such secondary manifestations at headache, nausea, chills, etc. In these conditions the use of oxygen is perfectly justifiable. From numerous observations, it appears that this gas generally acts favourably and gives rapid relief. Nausea and vomiting cease, a feeling of comfort supervenes, and this is followed by calmness and sleep, the frequent . and incomplete breathing- becomes regular, the pulse-rate rises, and headache disappears. Patients should make long and deep rhythmic inhalations. Eight 01 ten gallons of the gas suffice. The inhalation should take place through the mouth, the nostrils being tightly | closed so that nothing bii t the oxygen is taken I into the lungs." La Nature goes on \,o Fay that it would have been a good plan to try whether desp and regula "breathing would I not have piodv.ced a good effect, even without ] the oxygen.

— The Steljes iyr-swi-iter telegraph, for the exploitation of which a company has recently been formed, is an instrument which seems likely to have a good chance of success. • The idea of working a ipye-printing arrangement fi'om a Wheatstone ABO magneto-traiic-lnittei is at least 25 years old. It was, done by Stroh, and the mechanical details by which the apparatus was worked were of extreme ingenuity. A rnipber of these instruments, which were very compact, were, in we, but,

•unfortunately, they possessed a defect — i.e., they were not provided with an automatic zero-setter. This defect was a fatal one, and the instruments dropped out of use. In the Steljes instrument the very necessary zerosetter is fitted, and. moreover, the various parts have been well proportioned and subetantially made, with the result that a high xals oi speed, without danger of tripping, has been attained, whilst if tripping does take place, the resetting to zero is easily effected. Stroll printed both at the sending and receiving ends; so does Steljes. The power required in the latter's printer is derived from a weight; Stroh took his from a spring. Steljes uses a rubber typo wheel ; Stroh's was a metal. — Electrical Review.