SCIENCE NOTES

Evening Star, Issue 11892, 21 May 1903, Page 3

SCIENCE NOTES

A recent discussion at the Physical Society. raised some of the most interesting questions) in physics. It- anjae on a paper by Mr H. M. Ridout on the size of atoms. The author concluded that 114j millions of atoms of hydrogen are necessary to form a line one centimetre long. The method eraployed in the investigation consists in finding a pair of spheres which would be charged by the quantity of electricity known' to be necessary to electrolyse a given quantity of water to the known difference of potential of its ions. Lord Kelvin pointed out that the value arrived at by Mr Ridout for the diameter of a hydrogen ion was just about half that which he. himself had obtained for the diameter of a molecule of hydrogen. This might, however, be a merecoincidence. Lord Kelvin went on to deal with the atomic theory of electricity, which he says is now. almost universally accepted. In dealing with the size of atoms of the elements it is: necessary, he thinks, to consider the atoms of electricity, which lire very much smaller than those of matter, end penetrate freely the spaces occupied by the larger atoms,. and a'so freely through space not occupied by them. An atom of electricity in the interior of an atom of matter experiences electric force toward the centre of the atom,. so we have to conclude that every kind of matter haa electricity in it. If the electrons, or atoms of electricity, succeed in getting out of the atoms of matter, they proceed with the velocity of light, and the body is radio-active. It is therefore not surprising that some bodies are radio-active, but rather that not all matter is so. The whole subject evidently requires further elucidation, especially how atoms of one description can pass freely through the space already occupied by other atoms, and how, being frae, they are detained in the interior of the larter: If the report be accurate, Lord Kelvin's remarks must have been much condensed. * Experiments on newly-fallen rain) communicated to the Cambridge Philosophical (Society by Mr C. T. R. Wilson, show that the water collected from a shower has radioactive properties, though these last for only a few hours. The magnitude of the effect seems to be dependent upon quantity, though once, after a thunderstorm, it was abnormally large. t The action is shown by a substance obtained by precipitation or by evaporation. Similar precipitates formed in tap water or in rain that has stood for twenty-four hours are quite inactive. The official geologist for Pennsylvania of the U.S. Geological Survey and 'Professor "Hallock, of Columbia University, New York, have propounded a plan for using the internal heat of the earth as a source of mechanical power. Thefr' notion is to make a : deep bonng, let water into it, and use the steam and hot water produced. The Rev. E. Rattenbnry Hodges, in the ' Popular Science News' for January, 1894, made ft similar suggestion, but pointed out that it, was open to a serious drawback—namely, that " the cooling and consequent shrinking of the earth would be accelerated; in'other words, earthquakes would necessarily become more frequent, and possibly more violent and destructive in their effects." The professor and the official geologist do not appear to be joking, but in earnest. Si An unexpected effect of the eruptions 6f La Soufriefe has been experienced in the Barbadoes. The dust showers of October last destroyed many of the useful insects, but left the mischievous ones almost untouched. xA terrible disease called " heartwater" has destroyed immense numb?rs of sheep .and gofits in South Africa. The infection which causes it is carried by a species of tick known as the " bout tick\" This para-' site is in itself not harmful, and in its eg? stage, does not transmit the • virus, but ii once a larva acquires the infection it carries its power for evil until it is adult. The larvae may be' dropped in thousands from one infected sheep, and thus may decimate a flock that before was healthy. It is hoped that by exterminating the bont tick the disease may be stamped out. Mr A. Gallardo is a civil engineer of Buenog Ayres who has taken up the study of biology. Possibly owing to his professional habit of thought he has applied to the phenomena of cell-division and karyokinesis some theorems based upon the play of Newtonian forces of equal potential but opposite sign, and reproduced ,the spindlefigure and the phenomena of centrosomes by suspending crystals of sulphate of quinine in spirits of turpentine' contained in a trough. Into the' trough were introduced the wires from the poles of an electric machine. Working out . the theory in a pamphlet, and illustrating it by further experiments with iron filings-and magnets of varying powers, he reproduces in a very startling wav some of the appearances presented in the vital processes mentioned. Mr Gallardo regards heredity as being the transmission from cell to cell of the power to develop such forces in due course.' He avows himself a vitalist thus far, that he admits that the phenomena of living beings present problems and characters not found m inorganic or dead groupings of matter. The fashionable theory that instantaneous chemical reaction, if not all chemical action. is dependent upon ions—in other word 1 ?, that the reactions take place between electrolytes, has been put to the test by Mr L. Knhlenberg, who dissolved various salts in hydrocarbons which are not conductors of electricity. The solutions were found to be no better conductors than the. benzine used as a solvent, but the reactions were instantaneous and complete. The conclusion reached by the experimenter is that instantaneous chemical reactions are possible with non-conducting solutions as well «s with electrolytes. x Another attack .on the theory of the existence of ions in solution is made bv Julius Olsen in the 'American Journal of Science.' He describes experiments which show that an electrolyte which has never been acted upon by a current behaves as if it contained particles' charged with electricity, which are free to move, and these particles have not been produced by a current. This corresponds to the definition of free ions. Mons. R. Blondlot has tested by experiment the rate of transmission of the Xrays, and finds reason to believe that it is equal to that of the Hertzian waves or of light in air. A remarkable series of underground dwellings have been discovered and photographed in Ulster. Subterranean habitations have been found also at Waddon, hear Croydon, in England. Mr R. A. S. Malister reports on a prehistoric -cemetery-cave in Palestine, remarking that it afforded- the first discovery yet made of pre-historic inhabitants of that country who burned their dead. Above these remains were found unburnt remains of the earliest Semitic population. *~ — Some instructive experiments have' been carried out-on-the slow combustion of different forms of carbon. The diamond, when heated a little beyond the melting point of line, begins to burn veiy slowly without catching fire or giving any external sign. The chemist can observe that it is, losing weight and giving off carbonic acid gas. Only when the temperature is pushed lOOdeg higher does the. diamond burst into name. Exactly the same sort of result is obtained with graphite at the melting point of lead,, and with coke evidence of exceedingly slow combustion can be obtained at the boiling point of water. These slow combustions of carbon make it easier to realise how animal heat is maintained by ■low combustion of foodstuffs in the body They throw a light on the deterioration of exposed gunpowder, and also on the familiar perishing of coal that is exposed to the ■weather. The occasional outbursts of. fire in the coal bunkers of ships must be the outcome of slow combustion that has been going on for.a long time fiii enough heat baa accumulated to start a flame: The delicacies of modern chemistry are Bow so refined that the investigator is often troubled by difficulties like that of the al•btniat who discovered the universal sal-

vent but could make no use of his discovery for want of something to keep it in. Ihe action of alkaline solutions on glass nas led to careful observations on the action of lime, strontii, and. baryta . upon the bottles in which they are stored. Lime wa< found to be by far the most active, while baryta can be kept in glass "for twenty months without material loss of strength. lh.e doubt as to the usefulness of ouch solutions for Pettenkofer's (Dalton's) test for carbonic add in air led to the suggestion that paraffin wax should be used to coat the interior of the bottles, but all three earths are found to act on paraffin wax, baryta being much more energetic than lime or strontia.