SCIENCE NOTES.

Otago Witness, Issue 2719, 25 April 1906, Page 72

SCIENCE NOTES.

— The results of a study of phosphorescence in animals by Professor M'lntoah, published in the Zoologist, seem to have an inMortant bearing on the problem of the light of the future. The most striking thing 'about animal phosphorescence .'s the simplicity and economy of the mechanism by which it is produced. There is no waste of energy in the form of heat or other useless emanations, all is converted into light. On the other hand, in the— very best artificial light only a small percentage of the energy expended in producing it appears as light. A careful study of animal phosphorescence', then, may possibly lead to great improvements in our present methods of lighting. Some interesting investigations as to the cheapest form of light carried but at the Allegheny Observatory indicate that man must learn of the fire-fly and glowworm. This conclusion was the result of a careful speotroscopie study of the fire-fly's lamp^ and a comparison of the same with - sunlight. It was found that all the rays omitted are light rays, and that no energy is wasted as neat or other invisible radiations. Sir Oliver Lodge has" indicated how the phosphorescent lamp of the fire-fly may be "imitated. Certain phesphoresceat powders are ."to be introduced into a Grookes vacuum tube, and this is to be made to %lovr bypassing an electric current' tnrcugh it. — London Globe. , i — A writer in the Revue Scientifique, 'speaking of the inroads of the 6ea upon the borders •of England, says v thai l-ctw«*en Kibble and Dee, on the east coast, the land has been submerged since the fourteenth century, and the work is still going on. The walla of a castle that only 50 years ago stood half a mile from the sea- are now v washed by the waves. Near Land's End a whole region of 227 square miles has disappeared with more than 100 towns and villages. Since the time of T>lward I the area of the Duchy of Cornwall has been greatly reduced, and plainly so since' 1776. At Selsea, Sussex, ships now -^ast anchor along a line that is called "the pask," and -which was formerly a parfc for deer. At . Bexhill-on-Sea a submerged forest is visible at low tide. In Suffolk and Yorkshire many towns have been overwhelmed in comparatively recent times. Four hundred . houses were carried away in a single year at Dtuiwieh. : Between 1535 and 1600 four churches disappeared. In 1399 Henry IV disembarked at the port of Ravensburgh, but sicce 1538 Ravensburgh is no more. Eastern, once % an important town, could count, a century ago, only a dozen inhabitants and two houses. The 33 years from 1E67 to "1900 ware marked by • a reduction of the area of Great Britain from 56,964.260 to '56,782,053 jacres. -In a, third of a' century ,tho loss has been 182,207 acres. — Edison, the inventor, Las been asked by the New York Times what he considers will be the next most vital discovery in the scientific field. " Well," he replied," tLe control of energy stored in coal, directly .and without, waste. Ninety per cant. < f th<> energy stored in coal is now lost. It goea off in heat from the chimneys, and is especially wasted in the process of converting water into steam. If, therefore, means -can be devised by which this great waste can be obviated, it will naturally revolutionise- and vastly cbeanen the production of Dower. The result." adds . Mr lEdison, "will have- an incalculable influence upon the material progress of civilisation. It will enable an ocean liner of. say, 20,000 horse- i power to cross the Atlantic in unprecedented time, and with an-" expenditure of about one-tenth of the amount of fuel now requir-ed— 3oo tons instead of 3000 £ons. Coal will b-> put in a receptacle, a-sencies applied i for developing its energies with an inappreciable wastage, and through these agencies electric power of- any necessary; degree will bo forthcoming. ; Tt can and will be done'; some of the details are already mastered, practically." — There are peot>!e to whom gentle i and systematic exercise means a new enjoyment of health and longer life; others take un athletics in so violent a fashion as to lead to over-development, in so far as too much time and energy are given to certain systems of exercise, and the balance of Nature is destroyed. The hapny medium eeems to be struck in a book which comes from the Anglo-Danish Publishing Company, 188 Strand, London. It is entitled"My System," by J. T. Muller, who has been successively a lieutenant in the Royal I Engineers, a private engineer, and an inI sneetor of a sanatorium for consumptives. I He now proposes to snend hi° t ; 'np mi »-Ip- | veloping "ily System," in which, in ibp | book and aceompanyinsf chart, 18 forms of simple exercises are', laid down and explained. He nromispa health for 15 minutes a day' spent in his exercises. The write-r wa? at one time a delicate boy. but by a series of--£vmnasties and physical exercises developed himself into perfect physical condition. > The value of fresh air and' cold water is duly set down, although in our climate it is si counsel of perfection to recommend that every day you should let the "sun shine upon you," and also that you should not allow one day to pass without every muscle and organ of the body being set in motion. Stagnation, says Mulfer, leads to drocpine and untimely d-eath. Motion is life. He directs special attention to keeping, the skin in health, and to cxercisinar the middle of the trunk of the body, which is moat neglected. Skin gymnastics and exercises of the muscles of ti-e waist are what nine people out of every ten, ho tells us, stand most in need of. ;—; — The movement for the teaching of science in "schools year by ye&r assumes greater and increasing prominence. At a recent conference of the public schools science masters, certain plain statements were made regarding the necessity for increased science- teach ing as a means of fittine the pupils fcr their work in the world, and for conveying to them what we all need— namely, correct ideas of the universe in which we live, and of our relationship to that universe. We are coming to see that the exclusive classical education is a mistake, even for the clergyman or the lawyer. I am not of those who would eliminate the classics from school studies. They form part of general culture ; they bear a. relation to a knowledge- of literature; and they also are closely identified with the us* of scientific terminology. But that the purely classical-bred student is apt to fall by the wayside in the general knowledge of Nature is a self-evident fact, and it is not a. pleasant onft to face as a result of modern education. For the average lad, less classics and more foience — more bridging over the gulf betwixt the school and the ■world— would represent that happy mean wherein most satisfaction dwells. — Andrew "WJsoßj in the Illustrated London r _

— It is quite possible that the device of the radium clock may be so perfected from a commercial point of "view that we may have on the market a "elook" which will go for at all events 20,000 years. Mr Martindale, the well-known manufacturing diemist of London, is the inventor of this phenomenon in clocks, and a writer in the Scientific American describes the device in detail : —"The instrument is very email, being inclosed in a mahogany frame measuring about 6in by 4in. There is a pmall glass tube in which is placed about one-twelfth of a grain of radium, and supported in on exhausted' glass vessel hy a rod of quartz. At the lower end of this tube is an .electroscope, consisting "> of two aluminium leaves or films. The surface of the glass vessel is treated with phosphorio acid, to render it conductive. At intervals of one minute the silver leaves under the action of the radium move apart and touch the eides of the glass vessel. This action is caused as follows: After the Beta rays are carried away, the positive charge which is left behind is passed on to these two leaves. Under tl is stimulus they expand until one of them touches the 6ide of the glass vessel. This contact causes the charge to be conveyed to the earth. The leaf then falls back to its original position, by gravitation, when the cycle of operations is once more repeated, and continu-ad until the circuit is broken." The exact and continuous regularity of the movements turns the "instrument into a clock, the life of which is estimated at come score of thousands of years, so that, although the problem of perpetxial motion has not bpen solved by Mr Martindale's remarkable invention, it is not exactly hyperbole to speak of a clock for eternity. — The etrai^htest thing in Nature orJ art is a Tay, of light when passing through a medium of uniform density. Hencs the eye is enabled to test the straightnees of an edge or tube by holding it as nearly as possible coincident with a ray of light, such parts as depart from straightness then intercepting a ray and causing a shade to be cast upon other parts. It is not known at what early period in the- history of mankind the discovery was made that straightnees could be thus determined. It is certain that thousands of mechanics use the method daily without* being able to give a- rational explanation of it. — To te3t the presence of coal-tar dyes in such things as jam, fruit syrups, or. any other very red article of food, all that is necessary is to boil a piece of white woollen cloth, first wet thoroughly with boiling water, in the suspected article for five or ten minutes, and then wash out the cloth in boiling water. The natural colouring cf the fruit will leave the cloth only a dull pink in hue, while artificial dyes make it a brilliant red. Honey is often adulterated with glucose, and its presence can be discovered by putting some of the honey in strong spirit of wine. If . glucose ie present, it will cause turbidity in the spirit, and will eettle at the bottom Jn a tbi^k, gummy mass, while genuine honey forms into aflocculent precipitate, and when it has settled, leaves ho turbidity. Adulterants are not always added because they are cheaper than, the genuine article, but the public have a right to know when they are us-ed ; and it would be a distinct pain if,' in caee of suspicion, a simple test could always be applied. — A commercial war of great magnitude has been in progress * for some time, and the end is certainly r.ot in sight. The steam engine is being attacked by gas and oil : electricity is in a similar plig-hto The drift of competent opinion in certain directions,, says the - Engineer, of London, ie to tho effect that electricity has seen its beeb day. Indisputably the improvements which have been rendered possible in gas lighting by the thorium mantle have gone far to justify the- assertion which has been made that jjas is the best illuminant in the world. Eut the incandescent electric lamp may yet be improved, or even superseded All that can be said at present is that the future .of electricity seems to lie in the field of power distribution rather than of lighting. Gas lighting would have beaten electricity out of the market some time eince if it had not been for the immeasurably greater excellence of the latter in all that concerns cleanliness, heating, and purity of air. But improvements are daily being made in gas lighting, unparalleled by anything that is going on in electricity^