SCIENCE NOTES.

Otago Witness, Issue 2686, 6 September 1905, Page 76

SCIENCE NOTES.

— The beautiful series of experiments of lamsay and Raylejgh which led to the us.- . lovery of ar,gon and x«n.on show that as pu udvauce is made in -the direction , of ext.Teme -accuracy entirely new facts of the higiKsfc importance may be brought to light, i "The very perfection of ih& methods by which ] such discoveries are made is quite sufficient ' to .dispose of the ' thoughtless taunt that ' 1 they ai6i made by accident. It is also | astonishing {saj-s - a scientific- writer) to ' ■what a degree of accuracy a very small ' f , quantity of a substance can be percei-ved by our ordinary senses, unaided -by any ! special experimental apparatus. The ! *.50,000,00Qth part of a milligramme of-mer- ! -captan has been recognised by the sense,' of smell. On the -other hand, the' 14,GO0,O0Ot'h part of a milligramme of I Bodium Has bean' distinguished by the speetrqscope. —In an article recently published in ho Gaducee, as quoted in La Nature, Paris, "an old naval sturgeon, Dr tegrand . . . says that of all the, n means of relieving osa-siokness only one, Jis really effective ; it is to maintain the Abdomen absolutely rigid from the moment' of, sstting ' toot on. the vessel. To do this, J%, belt of, ordinary tightness is. 'insufficient/;;"^the ab- ' dooien must be bandaged with a'- layer of j 'tr&ddmg aud wide- bands of flannel — in g. • word, absolute 'compression-, must be at- - "tamed, care being, taken to do the bandag- j ing from Below upward,' ■S'owa'rd the chest." I -'Dr Legraad- adds-: /'The " important thing is 'not to be 'afraid to make the bancT too ' tight; otherwise the complete suppression of the symptoms cannot 'be obtained." „ ';._, — In a recent number of the journal of 1 * jjthc American- Medicals Association, Dr L. | JS. Dixorj, of Boston, calls attention to the "fact that the eye varies as much' as every- | ,thin^ else in the .human body. "Each per- 1 . scii/' he states, "is born with his ovm j ipair of ' eyes ; sometimes they are correct, nofc so . Often they are not alike' 1 and cannot' work together properly, ', Vision .. (is corrected by* the eih'ary muscles, which . pxp> made to work ; but when they are x>v£r- , taxed, they are. liable to 'exhaustion,- liH-nd ' this, in turn, gives rise to serious consequences." . If the eyes can once learn, [how to rest, they are" usually able to bear,; their , .overwork a fair share of the time' wijjhput '. ibad results; but they must have t 'rest and t-i frequent intervals. If igiass.es .are needed at all -they^ are realljv njqre- „ beneficial^ when worn, for/ resting ov jdi^taivt' vision than for close- work j but" that fstSe opposite, the, author says, to what ( people i" wish tt> do or find agreeable. Glasses <k>' r joot do a bit of .the work the eyes ought - k> do; they simply correct imperfections. Jn conclusion, Dr Dixon states thai, oon)rary to ihe general idea, s>harp, ! clear Sight, so highly prized and the boast of . many, is no.t the proof or the test of the good eye -, for many who have the keenest; , vision ca-nnot use their eyes much or' with -,r, r any comfort. Easy, vision, he maintains, vision that can be ussd and enjoyed freely, without thought^or fatigue, is the proper best 'of a good eye. — The man in the street-^-if his street 1 be situated in any large tow.n — 'will- " have , • noticed tie rapid change which has lately come over many^-of the- electric arc lamps •^..used to illuminate -the exteriors of 'various trading establishments. In place of the pure white glare — cold and • unkind " in its whiteness— of the usual form of arc light; | r a still more glaring radiance. bu,t of ? $< and pleasing golden colour, calls at- -. tention to the trader's miscellaneous wares and to his enterprise. The goldefi colour *, of the light is due to a peculiar^ preparation of the carbon pencils, .which are said ■ -to contain the salts of various; somewhat i t rare minerals ; but their exact constituents s »re not revealed by the manufacturers.- The light gives a curioas - spectrum quite- 'Tin- , f liks the continuous band given by ordinary 7 cartons, .which- is very, similar to that» : of ,j daylight. The spectrum yielded »;by "tne • new carbons is discontinuous, and consists: tof-a number of brilliant stripes separated , ;by spaces of darkness. The red', orange, : 'and green are especially conspicuous, while blue and the colours beyond are scarcely , represented. "The carbons have the "disadvantage of "giving' a somewhat unsteady lig-htj and for this reason they are more „ suitable for advertisement purposes than ' for interior illumination. Moreover, they ( \gi,ve off some objectionable fumes, which '/militate against their use in any bui- u «x- ' J oeedingly well-ventilated interiors. ... ' .. ' — Thomas A. Ed:son has been devoting his days for some jtime past to_ a keen search, for' radium, the newly-discovered jmj&tal) which promises such wonderful _re ' 'Stilts in healing the sick, making the -blind' lo fee, and curing malignant cancers. 'Jri an interview with a representative c£ the (New York World, at Menlo Park, a few 'nays- ago, Mr Edison said: — "I have hunted itoi't th ; s ne»v substance in a thousand plaoes fend chemically examined no end of specimens of one from different mines and JnountainS) but thus far have not succeeded In finding it in any quantity. I have, how"&ver, reached l some decided 'conclusions on . the subject. Radium is similar to X-rays itt its power to pass through substances, its effects are apparently as injurious to investigators. This is especially true pi the X-rays. My wife is unwilling to 'have me experiment with them any more. One of my eyes was drawn out of focus, and my stomach was more or less affec-tvid. so that I was seriously inconvenienced in my laboratory work.' Besides tliis, 'niy assistant died a;bout a yeav ago from the effects of their baneful influence; and now his brother, another assistant, is suffering from a red d'scolouration of the flesh on has breast and arms, although he has not been making any X-ray experiments for a year. Strange that the injury from their infkv

I ence should only manifest itself 12 months | after laboratory investigations ceased !" i — After Man — What?— Boss ihe process of evolution jeac-h its consummation in the human raoa, or is man ultimately to taki [ his place among the extinct M?-?Cies and to be superseded by a new and, presumably, higher type of earthly bsing? Discussing these questions, Dr S. W. AVilliston, Professor of Paleontology in the University of Chicago, writes in the New York Independent: — "'We have never had to d>eal with intellectuality as the dominant characteristic of a species in past history. Through it or by it man has largely mastered all environmental adversities, has conquered or is conquering other forms of life. But not all other forms. Even as it may have been the insignificant creatures which brought final grief to the mighty dinosaurs of the past, so, too, it is the microphytes and the rnierozoa which still set man at defiance." The conclusion of the professor is that, though man can probably never regain organs or functions, cnoe lost, he may acquire other organs and functions which will in part subserve them. Within man's narrow lines of evolution there are, speculative!^ vast possibilities yet. — An interesting reason why ships' bottoms painted with ordinary oil paint show considerably niore rust than those painted with special composition's was given in a paper before the Institution of Naval Architects. f Th'e rust is almost invariably due to the presence of moisture on the surface of the ship plates before the paint 6r composition is applied. The painting of ships, «s Mr Holzapfel pointed out, is generally done- in the daytime, when the temperatuio surrounding the vessel is about lOdeg to 20deg higher than the body .of the ship. As a consequence, moisture is generally present on a snip's plates while she is being coated; the quick-drying varnish paints which are used as a p^riminig in connection with the anti-fouling^are," however, particularly well adapted to prevent damage from the presence of this moisture, for during 'application the moisture becomes m&ed with paint, and evaporates with the several light hydro-carbons which aa-e generally contained in the paint. — Oassier's Magazine.^- — It has often been, a matter of comment that, although the ordinary view is that the moon's surface is no -longer subject to change, yet the contrary opinion is held by selenographei's. Professor , Pickering, for instance, while talcing into full . account the difficulties of observation arising the varying illumination of ,the sun, holds that the< volcanic activity "tin the surface of the moon is greater than on the. ..surface- of the earth. Professor Turner . maintains that it is far bettor established that changes are going on in ■the mobn tlian that there are double canals in Mars. The question has come to the front sinoe last July, when Professor Pickering detected a change in the circular plain, which can be seen through even a small telescope, and to which is given the name of .Plato. Plato has always been an interesting object of study. * Twenty -three years -ago 'Stanley Williams .saw a broad beam of visible light on the eastern side of the plain, slightly to the north of the centre. Smaller and fainter rays were also seen on the south side, and almost the whole of the plain was flooded with a pale, milky light. Five years before, he had noticed a "similar phenomenon. Five years ago two -astronomers, witching a small crafc&r to the south of Posidonius, saw it suddenly disappear before their eyes in a kind of wUi^ish. cloud. Charbonifeaux, observing another crater, saw it visible for a few moments, then it disappeared apparently in a whitish cloud, then reappeared, and so on at irregular intervals. There are plenty of reasons for believing that changes on the lunar surface should be taking place even more rapidly than those of which we are aware on the -surface of the earth. During the long lunar night of 14 of our days our satellite is exposed to the intense cold. Then comes the long Innar day, in which the crust of the planet is raised to a heat oi-some 3COdeg. Fahr. These tremendous alternations miist be the cause of continual disintegration, especially -as the processes are being repealed month by month. — West- j minster Gazette. I —Mr George A. Lowry' s latest invention, j the Auto-cotton Pielser, is the subject of I a special article by Mr Robert Cromie in the Manchester Guardian. The machine is j operated by one motor-man and four men or boys for picking. Each of the I "hands" is provided with two mechanical arms. Along these arms an endless belt runs at a high rate of speed, and the belt is studded with hooks, which snatch the cottorT from the open, boll and pass it along to jthe brush, which sweeps it off into the receptacle provided for it. The machine, which multiplies the output of each person upon it by four and a-half times, may work a revolution in cotton production. Mr Lowry is an Irishman^ He went" to America in 1875. He designed an automatic hog scraper and hoister, ""which pract'oally revolutionised the provision trade. Another interesting invention is a new twine of Asao grass, with which millions of acres of American swamps are covered, woven into matting, hearthrugs, screens, etc. The Lowry Cotton Press or "Round Bale" can be pressed as hard as pinewcod. and, in addition to cotton, it handles all fibrous products, such as wool, hemp, etc. The hay shipped from America to the troops in South Africa was pressed by ttus machine.

Eaiasrs of Poultry should use Nimmo and Blair's Game and Pottltry Meal, which is composed of the best ground bones and shells, specially prepared to meet the requirements of the fast-increasing poultry industry. It is made up m 24} b bags, at la 9d each. Ask your storekeeper fgi ji