SCIENCE AND INVENTION

Nelson Evening Mail, Volume XLVIII, Issue XLVIII, 3 November 1914, Page 8

SCIENCE AND INVENTION

LUMINESCENCE OF NITROGEN

It lias been found that nitrogen, vigorously and speetroscopically pure. acquires a continuous luminiscence. during the electric discharge, and therelore this phenomenon can no longer be attributed to the presence of traces of oxygen. In the presence of metallic vasuch as those of . rrercury, sodium, or potassium, the phenomenon is not produced owing to the nitrogen's being atacked by the metallic vapours, fomnng." it combination of the metal witfc nitrogen. The presence of cxy-gen-t which oxides the metallic vapours, hinders their action on the active nitrogen and renders ats formation possible. MOVING PICTURES PAUSE.

A new moving picture projector, with special driving mechanism and special sputter, makes it practicable to s'top the Sim at any point and project any .single Sfew on the screen as a Lantern slide. has been hitherto impossible because She heat of the lantern would ignite "or melt the celluloid or gelatine within a few seconds. In the new- apparatus starting and stopping aro controlled by a. clutch, and the film is protected by a shutter that is placed behind instead of in; front, and not only intercepts directly: much of the heat but is made to give a'-'powerful cooling blast of air by increased speed of its fan shaped set tors.

MECHANICAL FLOOR CLEANERS

- Tie janitors of many large office buildnow clean the floor with a convenient, compact- and virtually automatic machine. It consists of a flat carriage a few inches in length and width, mounted oa wheels fitted with noiseless ballbearings. The lower part of the carria£e T \- contains detachable revolving brushes driven by an electric motor. The macHSe haji a handle like that of a lawn since it weighs at most only can easily push it over a polished surface. The brushes clean the ffebrs thoroughly in one-fifth the time required by ordinary hand labour, and leaxe them polished '. The necessary electric—rurrent costs about a cent an noitT. ~

STEEU FROM THE EARTH - In Ldrdello, in Tuscany, there is a power station that gets the heat to generate thejteam .for its 180-kilowat steam turbine from the bowels of the earth. In that- neiaKoourhood there are several places wfc£re steair- under considerable pressure rises from the earth. The steam, however, -5 so saturated with boracic acid that'll can be. used to run a turbine ■■ enginer only by the indirect method of so conveying it round, the tubes of a special ft&id of boiler as "to heat the purer."water within . them. The firs* plant to us© the steam from the earth in this wsyl has proved so successful that another"of much greater horse-pow-er will be~established. "It is an interesting fact; that condensing the "natural" steam 'riiito water, and then evaporating the water for its borax, has been for many years a local industry.

IMPROVED SEA ANCHOR. Matters pertaining to tho sea and lifesavins devices are'more than ever <>f interest to the public. For protecting a lifeboat in a heavy sea, a device called a sea anchor is 'used. This consists of a triangular piece of canvas lashtd to a rigid frame. In a new and improved anchor''a cable ct chain bridle is arranged to'keep the lower point of the canvas triangle submerged, while oil oozing frorr- holes in the bottom of the cvlinder smooths down the waves and prevents "combers!! from breakup and swamping the boat. As the anchor hoids the boat head on, the action of the wind and =\\ ; ayes scarries the oil covered water past the boat. A number of these sea anchors are in use in the Army Transport Service, while the lifeboats of some of the large passenger vessels are being equipped with this latest patent device. ~

STUTTERERS' HASTE. - Dr. Alarage of Paris, told the Academic des Sciences recently that stuttering—which is an intermittent nervous condition of all sound-producing organs, lungs, larynx, and month—can be cured by making the victinE understand his affliction and the meafis by -which-'he can rid -hinrself o£ it Dr. iMarage showed moving pictures pf .the mouths of normal and stuttering persons, and of the vibration, of their-voices. These show that stutterers speak their words three times as rapidly .as normal persons, that the words are:' separated by intervals only-half as longhand that there is no division of syllables!" 'The stutterer talks rapidly because hefbreathes badly and is always out of breath. Therefore, the first treatment for him is to teach him to breath correctly. This can be done by exercises that any physician • should be able to devise. ULTRA-VIOLET MICROBES That ultra-violet light is able to produce new species of microbes is the startling announcement made by Mme. Victor Henri, -whose -work together with M. Henri in this field is already -well known, having been- carried out at the Paris University laboratories. Like all specimens, microbes are divided into •well-defined, recognisable species, and it was observed that such species reproduced in like fashion to produce siirilar specimens, with the exception of some ' flight variation such as give rise to attenuated types, these latter being used for vaccination." But here we have no longer to do -with a simple variation, but with a veritable mutation, that is, the formation of a new species -which dors . not '. return .to the ancestral type. The author operates upon bacteria which pro duce the disease common to animals, kncrwn as charbon, and according to a paper read before the Academy of Sciences, she exposes the bacteria for a certain length of time to the mitigated Action of a quartz mercury vapour lamp tvhich furnishes the ultra-violet rays Under these conditions, the microoes ore not killed,- as they would bo by etTong rays, but all are observed \; ho effected bv the rays. Arrong the icv tvpes which are formed in this way by the action of the light, there * nie, termed the gamma- form, which .s sei-n to be especiallv stable. For. three months the daily cultivation upon gelatine always produces the same type, and it is Concluded that this is a new' species.