SCIENCE NOTES.

Otago Witness, Issue 2860, 6 January 1909, Page 76

SCIENCE NOTES.

«*• Alzen is the name given to a new metal .which is composed of two .parts of aluminium, and one part of zinc. It is said to eaual cast-iron in strength, but is much more elastic. Alzen is superior because it does not rust, and it takes a high polish. — By rubbing metals with salt before applying merctiry, says the Engineer, the ancients obtained a reaction, similar to that for which copper sulphate is used. The chlorine released from the salt formed a sih er chloride easily attacked by mercury. - — A student at Rochefort i 6 reported by the Petit Parisien to have discovered a substance called "molybdott," which is said to possess the same properties as bromide of radium, and costs only. 20 francs , (16s) per gramme, instead of 3000 francs (£120). It is reported' that the discovery was made while the student was working for a com.-, petition in scientific photography. — Magnetic observations of the extinct, volcano called the Puy dc Dome, in Central France, have brought out the curious fact that the mountain is magnetised, not merely at certain points, but as a whole, the top of the dome acting as a south magnetic pole. Singularly enough, similar observations on the Kaiserstuhl, a mountain in Germany, indicate that it possesses a norfeh magnetic pole at its summit. — German surgeons made the discovery that the delicate membrane that lines the inside of an egg shell will answer as well as bits of skin from a human being to start healing over by granulation in open wounds which will not otherwise heal. The discovery was used for the first time on a. patient in the Seney' Hospital in Brooklyn, and it proved to be a successful trial. Tho patient left the hospital and resumed his customary work a healthy man. — L' Electricien quotes an instance of the accidental tapping of wireless telegraph messages without the aid of antennas or any special apparatus. It states that a Brunswick scientist noticed that an arc lamp in his laboratory was flickering, and on observing the lamp more carefully he discovered that it was delivering a telegraphic message in the Morse code. On making j inquiries the scientist discovered that the \ messages were those emitted from a wireless j telegraph station three 'kilometres away from the laboratory. I — The omnipresent automobile was pressed into a new field of service the other day, when the printing plant of the Bloomfield Citizen (U.S.) broke down owing to the failure of the gasoline engine. The ■ accident occurred during the. running of the regular edition, and emergency repairs were out of the question. The timely arrival in his automobile of a friend of the editor solved the problem. The automobile was backed up to the rear door of the printing office, suitable connections were made from the engine to the cylinder press, and the edition came out only a few hours laic. — Captain G. K. Gandy has improved the j ordinary canvas cover of a ship's boat, co as to form a buoyant Taft, by the introduction of cork and bamboo cane. This additional element of buoyancy occupies no more room and adds very little weight to the customary equipment of a ship's boat, and possesses the material advantage of being in the most natural and convenient place on a vessel for use when occasion arises. To lower a boat its cover must be removed for the operation, and in the case of a buoyant cover it can be either laid «fiide or thrown overboard, and, being attached by a line, is there afloat ready for any emergency. j — The following method of making a cheap barometer is practised in France. Take eight grams of pulverised camphor, four grams of pulverised nitrate of potassium, two grams of pulverised nitrate of ammonia, and dissolve in 60 grams of alcohol. Put the whole in a long, slender bottle closed at the top with a piece of bladder containing a pinhole to admit the air. When rain is coming the solid particles will tend gradually to mount, little star Crystals forming in the liquid, which otherwise remains clear; if high winds are approaching the liquid will become thick, as if fermenting, while a film of solid particle^ forms on. the surfaces during fair weathev the liquid will remain clear, and the solid particles will rest at the bottom. — Scientific writers have conducted a prolonged controversy respecting the origin of yeasts, some authors contending that they are entities, whereas by others they &r"a considered as phases in the development of higher fungi. Beoently Viata and Pacottet announced that Gloeospo*ium nervise«mum gave origin to a yeast. G. Bonnier describes in Comptes Rendus his attempt •to corroborate thte statement. After eight months' growth of a pure culture on various nutrient substances no formation of a yenetlike body could be detected, although the characteristic conidia and' pyenidia of Gloeosporiura was {produced, and the conclusions j arrived at is that the statement made by Viata and Paoottet arose from the presence of some impurity having gained access to *he.'t cultures, and, further, that ycast6 mu-t •to '-psrarded as autonomous plant-?. — That the attraction of the sun and rru ~" not only causes tides in the ocean. It !as a corresponding influence on the k<"! ' earth itself, has now been definitely pro-.ed by Dr O. Hecker, a Prussian phjpi<i=t. A quarter of a century ago Professor C. H. Darwin concluded that there must bo tides in the solid earth as well as in the fluid seas, but h& was unable to detect them.^ and his. only conclusion was that the earth's mass was very rigid— at least as rigid as steel. Dr Hecker now confirms this conclusion, but with his improved instruments and' methods he has been able to detect and measure the amount by which the . moon pulls the eolid earth out of shape twice a day. Dr Hecker's measurements, •which have lasted continuously more than iwo years, were to ascertain the lunar influence on the earth's gravity iby observing th~ oscillations of a delicate pendulum. It v«s by comparing his results with the" firn're* as calculated for a rigid earth that hr was able to detect the tidal deformation i.m- od by the pull of both moon and Bun. Tl-( series of observation* have now estab-li'-!:-c' the existence of lunar and solar IkU] vs'i- in the solid but flexible mass of the g V - . A- pure water, mineral irater. p^ro- '•- : n, jras, and heat can be obtained f:o»ii *]?~p borinr-s. it appears worth while remarks a writer in the Scieniifl" American) to !:i<fk-^ an attempt to obtain electrical energy from the interior of the earth by the same means. I have already published numerous inetaiices of the magnetisation of driven well tubes. Some lubes, driven less d:.n a thousand feet into iJir» earth, became

' magnetised strongly enough to sustain the weight of largo iron keys placed in contact with the protruding tops of the tubes. We know furthermore that a measurable electric current is generated when two electrode?, connected by a wire, are immersed in solutions of different temperatures of different degrees \A concentration. Now the earth contains various liquids, the pressure and temperature of which increase according to their depth below the surface. This distribution mu6t produce electric currents, and these may possibly be the most available subterranean source of electric energy, for to eveiy depth corresponds a certain constant pressure, and when this pressure is removed (as by a boring) the temperature immediately rises. — What is probably the largest example of petrification has recently come to attention in Arizona. It consists of the trunk of a tree, with branch stubs still intact, Which has fallen across the head of a considerable canyon and there "turned to stone.". The huge roots of the fallen I monarch rise to a height of Bft or 10ft at one end, while the upper extremity of ] the trunk is buried in the soft formation of the land in which it grew. The trunk ie more than 50ft long, and spans a canyon At least 40ft. wide. It forms a perfectly solid bridge of a diameter of from sft to i 2ft at Ihe smaller end. Tiees of considerable size have grown up around it from the bed of the canyon, some of them considerably higher now than the fallen tree v long. Over the trunk of the petrified monster they throw a welcome shade to the birck which gather for miles around to sit on the stony trunk during the heat of the <lay. This tree is a considerable distance from the Arizona petrified forest, and ie one of the wonders of the great desert state. It is considered quite probable by miners who have seen the tree that its interior portions are practically solid agate, as are those of other petrified trees of Arizona ; but no one has been venturesome enough to cut into the great natural palseontologTcal bridge to find out. , — During the volcanic eruptions that occurred in 1902 at Mont Pelee, in Martinique, and at the Sotifricre, in the Island of St. Vincent, respectively, the vegetation of those regions covered by the incandescent avalanche was totally destroyed. In tome districts near Mont Pelee the avaI ianche of lava is several feel in thickness I and the surface has consolidated into a crust nearly an inch thick, almost like a concrete pavement, and where this crust is perfect no vegetation can spring up. On the other hand, where the crust is broken up by watercourses, or by the trampling of horses and cattle, vegetation is reappearing, silver ferns (Gymnogramme calomelanos), grasses, and young* Plucheas being present. In other districts, where the hot ash was only deposited in- a thin layer, the roots of trees and shrubs were not killed outright, and are now throwing up new shoots and leaves, and the ash is rapidly breaking up under the influence of plant roots, and humus is being formed. The new vegetation consists of castor oil (Rioinus i communis), which is" very luxuriant ; Pluchea odorata, which has formed bushes higher a man ; indigo, sensitive plant, guinea grass, etc. At altitudes exceeding 1500 ft only a few grasses and silver ferns are met with, and at yet greater elevations nothing : but mosses and lichens are found. — There is a very ancient belief that a blood vessel extends from the base of the fouith finger of the Jeft hand to the heart, whence, as is alleged, the choice of that finger for ihe wedding ring. In literature allusion to it is made a« the "Vena amoris. ' or love's vein. Unlike most notions of the j kind, this idea is entirely correct, for a vein does arise directly at the root of the ring finger, and. running- over the back of the hand, finds its way through the "royal" vein, the "auxiliary," the '"subcla\ian." and the "innominate to the heart. This vessol is very conspicuous, standing out clearly when the hand hangs limply downward. The reason for putting the ring on the fourth finger, however, is probably quite different. Its u«e for the purpose goes back to prehistoric tmip*. and its selection is likely to have been due to the fact that it is the least freo in it-s movement"! of all the fingers. Accordingly a ring encircling' it will interfere 'ess with the use of the hand than if p ; aced on any other digit. It happens that the extensor tendon of the fourth finger is attached to tho<=e of the third and fourth fingers by cross-bands which restrict the movements of the ring finger considerably. Anybody may test this for himself by holding the third and fifth fingers forcibly bent and trying at the same time to extend the ring finger. — Popular Science Sittings. — Su-gery by electricity is what "s alleged to be possible with a remarkable electric knife just devised by a Berlin firm of medical instrument manufacturers. The knife is now undergoing- exhaustive trials at the hands of Professoi Bier, the head of ' the University Surgical Clinic, with the view of demonstrating it=. efficacy. It is declared that operation-; can be performed mdro quickly au.d that thp healing pro cess is J»or« r*pid than in the cases wher<» the ordinary *c»lpel has been used. To one end of a 6in or Bin glass rod, through tho centre of which passes a conducting wire, is -fastened the blade without a cutting edge, of a form similar to that of the commonly-used surgical knives, or like the simple probe. A high frequency current <s employed, and when this is turned on a noiseless spark £in long appears from the point of the knife or probe. The spark incises the soft tissues with the same ease as a. hot knife goes through butter, without any apparent cauterisation. But Professor Bier's experiments have so faa- shown that a more profuse hemerrliage ensues than by the U6e of the common knife. It is claimed for the instrument that it sterilises as it cuts, requires no sharpening, and can be easily cleaned. — The sensitiveness of the human or ganism is gross indeed compared with that of the marvellous machines man has made. A photogiaphic plate coupled with a telescope discover? millions of (-tars whose light the retina of the eye does not appreciate; the microphone makes the inaudible tread of a fl\ sound like the tramp of cavalrymen. The human heat sense cannot realise * difference of temperature be3"ond one-fifth of a decree ; but the barometer, an instrument 200,000 times a« sensitive as the skin, note* a differ-en<e of a millionth of a degree. A galvanometer fleve* its finger at a current generated by simply deforming a drop of mercury so as to pre=-« it out of a spherical shape into that of an egg. The amount of work done by the wink of an eye equals 10C.000.000,000 of the winks marked on the scale of a celicate instrument ; gut even this performance is surpassed by the "coherers"' of Branley of Paris, by which the

Hertz waves of wireless telegraphy are caught in their pulsings through space. The range of impressions which we get from lifting an object is exceedingly small; an ordinary chemist's balance is some million times as sensitive, and weights down the two hundredth part of a milligram. Sucih instruments as these make it evident that our sense organs give us reports of but a comparatively small number of comparatively garo3s stimuli.