SCIENCE NOTES.

Otago Witness, Issue 2603, 3 February 1904, Page 64

SCIENCE NOTES.

— Colonel Rcnard, the aeronaut, and M. Surcouf, an engineer, have invented a n< j w "automotor raiilces train " which, according to M. Maurice Levy, of the Academy of Sciences, will levolutionise road traffic, and may one day to some extent supersedcrailways. Small models were first built, imt a full-sized train of 10 cars, weighing 30 tons, has been now constiucted, and tested, and will _bo exhibited at th© Automobile Salon. The principle- of the invention is aa follows: — While the leading vehicle carries the motor, it is in no senso a traction engine. The cars are respectively connected one with another, not by mero couplings. Each vehicle is provided with transmission gear actuated by the- motor on the loading car. Each portion of the train is practically, therefore-, an automobile, as the engine on the first vehicle propels all the others individually, as if each of the latter had a motor of its own. Tho second point in the invention is the steering gear. This has been devised on the same principle as the transmission gear. That is to cay, the train of cars is not drawn in the wake of tho engine, but the latter commands the steering gear provided on each car. Thus the train forms a completely linked system. The advantage-s of the invention are apparent. Traction being lione away with, each car, as it we-re, propels itself, and friction of -ill the wheels upon the roadway ie utilised instead of being a useless resistance which the engine- nv.=;t ../vercome. Consequently a fnr !<~s<; p'-.-i < v r^\ motor will, other things equal, draw a far, heavier load than is tho case with tho traction engine. Moreover, the direction given to the train is not merely a straight line drawn from the leading car, as must occur with a railless train tugged by a locomotive. On the contrary, the steering gear -of each _:ar being commanded by the leading vehicle, tht convoy *an negotiate practically any curve. Finally, it is claimed .that the invention minimises the> risks of side-slipping. A special device to this end is a differential system by which, if needful, various speeds can be imparted at the same moment to various parts of the same train. A test to which tho invention has bc-en successfully submitted will give an idea of the advantage-3 of the system. A racing car whioh ran in^" the Paris-Bordeaux contest this year has been omployed as the engine of the -iew train, fli© motor was capable

f propelling tho cai alone, weighing 1500 kilos, at 444 miles an hour. Now the same engine propels tho train of 30 tons at over 11 miles an hour. Another test was a trial trip, in which the train, having the fame -■motor, Jimbed succossfullv the tremendous hill up to the heights of B-sllevue from the 'banks of the Seine. The inventors pay "every single high road in France is now open to train traffic at moderate spoed."

— The Medical Press (November 11) : — "An able essay on the subject of 'Race Susceptibility to Infection' was read at •the recent meeting of the British Medical 'Association by Dr R. J. M. Buchanan. The great value of his communication lies in the bird's-eye view it gives, of lace susceptibility throughout the nations of tho World. To tuberculosis, for instance-, the Gaelic and Cymrio race are considered more susceptible than the Saxon and Scandinavian. Negroes are very susceptible to (tuberculosis, especially in countries not native to them. Cancer is said to be rife in China, whilst ft is rare in Egypt, uncommon among n&groee, but prevalent among the blonde inhabitants of Norway. It is a well-known fact that smallpox is exco Bively fatal to people among whom it is introduced for the first time, as shown nmong the North American Indians, where the Mandon nation war* entirely destroyed by it ; and in_lceland, where in the earliest epidemic 18,000 out of 52.00( perished.

, Negroes are very susceptible to sleeping i Gickneas ; other races are not co. Jews arc believed to be prone to diabetes and nervous diseases ; Chinese are exempt from chorea ; the negro ie almoet exempt from, yellow fe\er, in which the order of susceptibility runs : Scandinavian, Englishman, Southern European, creole, mulatto, negro. The- unravelling of all these "various conditions, apart from their general interest, is likely to have a meet valuable application in modern therapeutics." — There was recently exhibited at the Fianklin Institute, in Philadelphia, by Frank A. Bnmner, of that city, a means of making photographs on pape-rs of the ordinary slow-printing kind Ui-ed by all professional photographers, without regard to the weather. The business of the professional photographer has been heretofore very largely dependent on the sun. A few days of rainy weather throws his business back ■ just tha' long, as he is unable to make 'prints without the aid of the sun. "With the machine referred to it is possible to do the work in half the time usually re1 quired. The invention embraces two features, one in the construction of the lamp j giving a light very rich in the violet raye, , which have by far the greatest chemical , action, and the other in the construction of a frame by which the plates are held around ' the light at the. point where they receive the greatest and moet diffused illumination. Tht machine is octagonal, occupying a floor space of about 3ft by 3ft, and each one of the spaces will accommodate a printing framo llin by 14in, or" a greater number of smaller ones. The daily capacity of the machine is a,bout 800 or 800 prints, sin by 7in. In the demonstration given, a print of a negative of i very dense character, ! which the operator said required 30min to ' print by bright sunlight, was made in 16 I minutes, while printe of a normal density were readily made in much less time. I — Anyone who hae taken a railway journey through the midland counties will know i well enough what is meant by the> "Black Country." Hundreds of acres are covered by the hideous accumulation of debris which , hai3 been dug out from the mines and [ thrown aside as useless material — the husks • from which the precious kernel h?u been abstracted ; and theso ugly mounds of rubbish not Dnly constitute a terrible eye-sore, but they represent a wilderness of unproductive soil. A meeting has lately been held at Birmingham with the object of find-ing-\somo rcintdy for thi> unfortunate state of tilings, and r mass of opinion has been collected in favour jf clothing these barren , hillocks with verdure, so that the country shall once more bear the earn© aspect as , ir had befors tho miner came upon tho scene am 1 changed the face- of Nature. It - s believed on competent authority chat these i waste places might again blossom as the | rcce and become once more fit foi the abode of human beings. Air Herbert Stone, who was Jie first to suggest action in this direction, proposes to so treat the coil that it should be suitable for the growth of sycamores, lime, beech, ash, elm, or poplar ; ! and Professor Firher considers that some thousands of acres oi Black Country might bo successfully plamcd with pine or spruce, so as tc yield a fair ieturn on the outlay in 30 years' time. On tho whole it would i soom that this attractive scheme is far ' from being impiacticable, and we can only • hopo that it will bo found possible to carry it Jntc effect. —Of the chemical activity of microbes, 1 what we know is as nothing in comparison ! v ith what it may be. Every species, every j race, every variety of microbe-, ie charged 1 vrita a special function; the division of 1 labour is carried among them to its extreme i limits, ec .much so that in any chemical ! reaction each microbe takei its part in ' pioaueing the piocess at diVerent stages. Jivch variety ha 0 its duty in the work, determinates a partial dissociation of the material which another species completes, and ! so on to the extreme- simplification of organic

matter, reduoad to its elementary constituents, cr to such condiiion-s as to be* assimila-blo by tho plant. Tho chemical actions determined by tho microbe arctherefore- infinite, and infinitely varied. Ta-ko two -cxample-8 among a thousand. Starting with a singlo body — sugar, for example-, — Lhe microbes may traivsloim it into dcxtrclactic or scrolactic acid, or an indiftere it acid, according to their own activity, the culture medium, or the associated reactions. Reducing agents in a high degree, microbes transform eulphat-es into sulphites, and even into sulphurets, th© latter yielding, still by means of mierobio icacuons, culpholiydric acid. As microbes derompeco dead matter, so they arc capab 1 © of disorganising living matter. Some- species havo this power in a marked degreo, which is distinguished as virulence. They are called pathogenic miciobc-s, which means capable of causing illness. Each species of this microbe produces a particular kind of disease, and h&r, a power that varies conpide.abiy, according to a number of circumstances. TLc microbe alone, however, cannot pioduce disease; that requires the intervention of the organism of the subject in wh'ch tho dvorder 1= to bo developed. The disease is, in fact, the resultant of th-o reaction of the one upon tho other of the two factor?, the microbe and tho organism. According to tho felicitous comparison of Fiof'-Sbor Bouchaid, the organism is a strong plpcc-, the- mkrobc is its assailant, and th© stiuggle between them is tho in-fectiou-s disease. Microbe-? have other equally important and useful offices. Of these- Ih their action 111 diccst'on. Ordinal y digestion Is performed in the stomach and th© intestine by means of soluble feimcnts secreted by the organic cells, -which attack alimentary substanr.es, chs-'ociatc them, and lendor them assimilable; and this is per-ce-ived to bo a^ function veiy rimilar to that oi niicrobe-s. The digestive passages, howcvti, contain immense quantities of microbes continually brought in with the food, multiplying infinitely, and performing exceedingly complex o Pices. Even if we take up only a few of tliesc office'?, we arc compelled of noceesity to assume that they jnterven© ii digestive operations, either as aids to the organic diatta-es or as thcmsel-'^s efTet tive agents. M. Duce-aux, insisting on this point, has remarked that some celluloses are oapaliio of being attacked only by microbes. Al. Jta«teur doo~ not believe in the possibility of digestion in a medium completely de-jji-ivtd of microbes. — London Sun.

— "Radium is ch-omically a metal, though at I>-'C!-ent only its salts are known. Profwer Ramsay has given d'rec-t proof that he hum is being constantly mad© by the gradual 'breaking up' of radium, but there is no direct evidence that there is a similar process going on among th© other metals. Th© 'philoropher's stono' has not yet be-en discovered ; but if it be truo that on© ela-me-it i-s being transformed into another by a natural process, it shows that the transmutation of metals is not the inconceivable thing that might be supposed." ''Two or three months_ ag-o," continued Piofeseor Masson, "Sir William Ramsay and Mr Shoddy gave experimental proof by means oi the spectroscope that tho salts of radium are constantly throwing off helium gas. This discovery was foreshadowed by the speculations of Professor Rutherford, of Montreal, one of th© chief investigators of radio-activity, and was confirmed independently by Sir William Huggins, president of the Royal Society. Radium and helium are two perfectly distinct elements, tao former of ve-ry largo and th© latter of very small, atomio woight, and tho inference from the discovery is that helium is produced by a process of degradation of the radium atom=. It is probable that Sir William Ramsay hae delivered a popular lecture on his discovery, and has pointed to it as a modern justification of the- old dream of the alchemists — the transmutation of the elements. It is highly improbable that h© has claimed to bo within measurable distance of l profitable realisation of that dream."

— The scratching and hissing sound heard when listening to a phonograph or gramaphone is due to th© stylus passing over the wax or ebonite surface of th© record. The noise is unpleasant, but though it can bo lecsened by keeping the records and tho stylus in good order, it can never be entirely don© away with (remarks th© Leisure Hour) so long as th© reproduction of sounds depends upon scratches on a material surface travelling under a blunt point in contact with it. An instrument has, however, been invented by means of which sounds can b© reproduced without the objectiorlable quality of the phonograph and gramaphone. Ihi- instrument depends upon a discovery by Herr Poulsen that if a steel wire is caused to travel past a small electro-magnet in circuit with an induction coil and a telephone and microphone into which n. person is speaking, it acquires magnetic peculiarities which vary according to the sounds of the voice. In order to reproduce tho sounds tTms magnetically recorded, it is nectary =imply to connect the induction coil with an ordinary telephone re-ooiv-ci and to pass th© magnetised steel surfaco iridcr the magnet. This is th© principle of tho Poulssn telcgraphone, described in the Scientific American There are two forms of tho instrument, one in which a strol vi ir© is wound upon a drum, which can be turned at a constant speed, as in Pdi--on's phonograph, and the other :n: n wnich a steel plat© is used similar to the di<e cf a gramophone. In each instrument, a c mall "lechc-magnofc takes the place of the srv'ui of tho phonograph nnd gramaphone, and as the steel v.iro or di«c move 3 under it the sounds are reproduced. Poulsen's instrument has been well tested, and looves nothing to bo defiired as to articulatioi and purity of sound.