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physical quantities. His results show no such variation.

Trujillo on Aug. 19. Before the end of August the Government had 6,000 men under arins. The steamer "Cova was bought from Grace Fluidity of Solids.-Dewar (London Chemical Brothers for £40,000, and was fitted out as an Society, June 7) finds that some other substances armed cruiser called the "Constitutional." All besides metals have the property of flowing unagricultural work, trade, and commerce was in- der pressure, while still others do not possess it terrupted by the civil conflict. The Mon- at all. Crystalline sodium sulphate, sal ammotaneros, as the rebels were called, seized the niac, graphite, and urea flow easily at 30 to 40 Oroya railroad, and when the Government sent a tons to the square inch, while starch and salt reforce of 2.000 men with Gatling guns to attack fuse to flow even at 60 tons. W. Spring (Belthem three fourths of the troops deserted to the gian Royal Academy) concludes that at a certain enemy. The rebels boarded a transport and temperature, where a metal still appears to be a liberated a large number of prisoners. They perfect solid, some of its molecules attain a state attempted to seize the Constitutional" by of vibration corresponding to the liquid state, strategy, but were detected and taken prisoners. and thus, by softening the body, make it capaThe Montaneros were armed with Winchester ble of being welded and of forming alloys. He rifles, and they were well fed, while the Govern- has welded metals kept for three to twelve hours ment troops received scant rations and no pay. at a temperature of 200° to 400° C., the best joints Robberies were committed by both sides. In being produced with gold, lead, and tin, and the the south Pierolist bands assembled, but they worst with bismuth and antimony. The more were not strong enough to contend with the crystalline the bodies are, the less do they show Government forces. The Chilian Government, this phenomenon. The occurrence of this inafter appealing first to the Peruvian authorities cipient liquefaction was proved by submitting to disarin the insurgents, occupied Tacna. On copper, on which a delicate spiral had been cut, Oct. 9 Gen. Osma succeeded Gen. Torrico as to a temperature of 400° C. for eight hours; at Minister of War. The Government made greater the expiration of this time the spiral had disapefforts to exterminate the insurgents. Gen. peared and the surface looked as if just fused by Borgoño led a large force into the north against the blowpipe. Alloys also were formed at the Gen. Seminario, who evacuated Cajamarca and same temperatures. took to the mountains. Gen. Pierola landed near Pisco with the intention of placing himself at the head of a revolutionary army at Chincha. The Government was informed of his movements, and a large body of regulars put the revolutionists to flight. The Government endeavored to increase its revenues by decreeing that the sole should be reckoned at 30d. in levying customs duties, which were thereby augmented 30 per cent. In the beginning of November all articles previously exempt were made subject to an import duty of 8 per cent. ad valorem. There was a Cabinet crisis, which terminated on Nov. 17 in a reconstruction of the Cabinet as follows: Premier and Minister of Foreign Affairs, Dr. Manuel Yrigoyen; Minister of the Interior, Leonardo Cavero; Minister of Justice, Manuel V. Morote; Minister of Finance, Nicanor Carmona; Minister of War, Gen. Osma. PHYSICS, PROGRESS OF, IN 1894. Constitution of Matter. The Ether.-J. Larmor (London Royal Society, Dec. 7, 1893) proposes to reconcile the elasticity of the ether with its yieldingness by assuming that outside the Vortices constituting matter it has a peculiar kind of elasticity called into play only by rotation. The atomic whirls would then meet with no resistance to their motion, while the ether would still be highly elastic to vibrations, provided these are rotary. Franklin and Nichols ("Physical Review," May-June) have endeavored to find whether the sudden stoppage of a rapidly rotating coil causes an electro-motive force, and find that if any part of the coil's energy depends on motion in the ether produced by its rotation this must be less than 10-17 of its entire energy.

Gravitation.-A. S. Mackenzie ("Johns Hopkins University Circular") has measured the gravitational attraction of a crystal for a particle along various axes to see whether it would vary as do the velocity of light, conductivity, and other

Mechanics. Elasticity.-J. O. Thompson ("Physical Review," March-April) finds that a fatigue exists in the elasticity of stretching analogous to that shown by Lord Kelvin in the elasticity of torsion. In a more extended research (ibid., May-June) he finds that it follows the same laws. The fatigues in copper, silver, and brass are nearly as 7:3:2 for the torsion and as 4:3:2 for tension. The temperature coefficient for both in all 3 metals is about. Mary Noyes (American Association, 1894) finds that in the case of a piano wire Young's modulus is lessened by heat and also by the passage of an electric current. Magnetism has no effect.

Attraction exerted by a Vibrating Disk. Berson and Juppont (Paris Academy of Science, Nov. 27, 1893) have measured the attraction between a steel disk vibrated electro-magnetically and a mica disk near it. The attraction is due to the motion of the surrounding air, as has been previously established. It varied from 602-3 dynes at a distance of 1. mm. to 2:55 dynes at 10 mm. To produce the same force electrostatically a potential difference of 600 volts would be required.

Liquids. Solution.-H. C. Jones ("Physical Review," September-October) has investigated the solution tension of metals-that is, the pressure which, according to Van't Hoff's theory, their molecules must exert in a solvent to bring about solution. The chief point brought out is that the solution tension of silver is not a constant for all solvents of its salts, but depends on the nature of the solvent. The same will probably be found true for other metals. Le Chatelier (Paris Academy of Science, March 19) deduces mathematically the fact that if latent heat of solution were independent of temperature and concentration, the normal curve of solubility of any given substance would be the same in all solv


Crystallization.-Pictet (Paris Academy of

Science, Oct. 1) shows that a crystallizing body loses heat in essentially different ways, according as it is adiathermanous or diathermanous. All substances become diathermanous below -70° C., hence the true temperature of crystallization is obtained only by keeping the surrounding medium slightly below the solidifying point. This explains various anomalies, as in previous determinations of the crystallization points of chloroform, etc. Moore ("Zeitschrift für Physikalische Chemie, December, 1893) has measured the velocity at which crystallization proceeds in a supercooled substance, by following with the eye the moving line of demarcation between solid and liquid in a U-tube. With acetic acid the velocity was found to be uniform at any temperature and independent of the diameter of the tube, and with this substance, phenol, and mixtures of phenol with water and phenol with cresol, the velocity increases with the amount of supercooling, but at a diminishing rate. For phenol the velocity is 0.6 cm. a second with 4:4° supercooling, and 2.9 cm. with 15-8°. The addition of water or cresol reduces both the velocity and the rate of its increase.

Cohesion. Kasterine ("Journal of the Russian Physico-Chemical Society," xxv, p. 51), from experiments on the variation of cohesion in liquids, and on the assumption that the molecular forces conform to Newton's law of the square of the distance, derives the following laws: 1. The product of the intensity of molecular action by the molecular weight is a constant. 2. For different liquids at corresponding temperatures the radii of the spheres of molecular activity are approximately proportional to the square roots of the molecular weights. 3. At corresponding temperatures the physical molecule in different liquids contains the same number of chemical molecules.

Density.-Kohlrausch and Hallwachs (Wiedemann's Annalen," October) have measured the density of very dilute aqueous solutions to within one millionth by weighing a glass globe suspended in the solution by a fine fiber. Interesting details regarding the molecular volumes of the dissolved substances have thus been brought out-for instance, phosphoric and sulphuric acids show a diminution of this volume at extreme dilutions.

Capillarity. Quincke (British Association, 1894), as a result of researches occupying forty years, finds that drops of oil floating on slightly alkaline water are attracted toward the walls of the vessel and then repelled, the spreading of the soap film that results from the action of the alkali on the oil giving rise to periodic vortex motion. Viewed with the microscope the film shows the same minute strings of pearly beadlike bubbles that are characteristic of protoplasm.

Viscosity. Owen Glynn Jones (London Physical Society, Feb. 9) has measured the viscosity of liquids by observing the velocity of small drops of heavier liquids falling through them. A water drop of 1 mm. radius was found to fall 1 inch an hour in castor oil at 8° C. This method has been criticised, the formulæ used being calculated originally for solid spheres, and the critics holding that internal motion in the drops as well as mutual contamination of the two liquids would complicate matters.

Hydrodynamics. - Prof. Osborne Reynolds (British Association, 1894) has studied the suc cessive stages in the motion of water passing under gradually increasing pressure through a vertical tube constricted in the middle. The water first leaves the constriction as a narrow steady jet, then it fills the lower part while eddies appear below the constriction, then the motion becomes turbulent, and finally there is an appearance as of air bubbles at the constriction with a singing or hissing sound.

Decomposition of Liquids by Powders.—Dr. G. Gore (Birmingham Philosophical Society) finds that when finely powdered substances, especially silica, are placed in a solution the adherent film of liquid contains more than the normal percentage of the dissolved substance. The amount of the substance thus abstracted depends on the kind of powder, its fineness, its quantity in proportion to the dissolved substance, the absolute amount of the latter, and in some degree on the temperature. The results seem to throw light on the purification of water by filtration.

Gases. Condensation.-In a lecture at the Royal Institution, published in "Nature," Dec. 28, Shelford Bidwell states his conclusion from his own experiments, that the dense condensation of steam produced under certain circumstances is due neither to electrical action nor to dust nuclei, but probably to dissociated atoms of atmospheric gases acting in some unexplained manCarl Barus (Nature," Feb. 15) objects to Mr. Bidwell's conclusions, and is of the opinion that condensation upon minute particles in the air will account for all the observed phenomena.


Critical Point.-Kuenen (Amsterdam Academy, May 26) has carefully investigated abnormal phenomena near the critical point, and concludes that they are due to impurities. From a repetition, for instance, of Galitzine's experiments, which have been supposed to show that ether above the critical point has different densi ties, according to its having been entirely fluid or partly vapor, Kuenen concludes that Galitzine's results were due to a trace of some noncoercible gas, perhaps air.

He now

Vortex Motions in Air.-Quincke announced in 1890 that two spheroids of a mixture of oil and chloroform, falling simultaneously in water, approached and receded alternately, owing to vortex motion in the water. finds (Wiedemann's "Annalen," July) that the same phenomenon occurs when two soap bubbles filled with coal gas ascend together. Similar phenomena occur when small dust particles fall in air, or liquid, or when a current strikes particles at rest.

Barometry.-Bartrum has invented what he calls an "open-scale barometer," which is described in Nature," March 22, p. 488. The lower part resembles that of an ordinary mercury barometer, but near the upper surface of the mercury the tube is enlarged into a bulb, above which it is again contracted. The bulb is filled with a red fluid, the upper surface of which gives the barometer reading, a small change of level of the mercury causing a large one in the fluid. An inch of mercury is represented on the scale by 9 inches, and it is claimed that the atmospheric pressure may thus be ob

tained to the thousandth of an inch of mercury without a vernier.

Heat. Thermometry.-Barillé (Paris Academy of Science, Jan. 29) has devised an electricaların thermometer for laboratory ovens. When the mercury reaches the desired point a circuit is closed by a platinum wire attached to a small iron tube that slides along a fixed wire and that is regulated in position by a magnet attached to the supporting frame. Baly and Chorley ("Nature," April 5) have devised a high-temperature thermometer in which the expanding substance is a liquid alloy of potassium and sodium. This alloy boils at about 700 C. and solidifies at -8 C., and the thermometer should be particularly useful for determining high boiling points.

Specific Heat.-Silvio Lussana ("Nuevo Cimento," abstracted in "Nature," Sept. 20) has obtained the specific heats of gas by an ingenious apparatus that uses the same gas over and over again, and thus obviates the necessity of a large amount of gas.

Expansion.-Max Toepler (Wiedemann's "Annalen," October) finds that the coefficient of expansion of elements in the solid state and their change of volume during melting show a definite relation.

Conductivity.-I. T. Osmond ("Physical Review," November-December) finds that the thermal conductivity of cast iron is about 15 per cent. greater from a little below 100° C. to 200 than it is between 60 and 90°. Saret ("Bibliothèque Universelle," No. 4, 1893), from examining the shape of the isotherms in certain sections of crystals of gypsum, finds no evidence of the existence of rotational coefficients of conductivity.

High Temperature.-C. Barus ("American Journal of Science," October) points out various anomalies in the accepted results of researches on high temperatures, and states that to clear these away either the boiling point of zinc must come down from 930° to 905° C., or else the melting points of gold, silver, and copper must move up 30° or 40°, or both must move toward each other by corresponding amounts.

Sound. Velocity.-J. W. Lowe (Wiedemann's "Annalen," August) finds, from experiments with a Quincke interference tube, that contrary to the results of Kundt, Regnault, König, and others—for closed tubes the velocity of sound in air and in carbolic acid is the same for notes of different pitch and intensity when they are propagated in open space.

Pitch.-F. Melde (Wiedemann's "Annalen," June) has devised a new method of determining the pitches of high tuning forks independently of the ear. The fork is vibrated with one prong touching a metallic rod clamped at one end, which is thus caused to vibrate transversely, and the pitch is determined from the nodes of this rod, observed by means of fine sand that has been dusted on it.

Beats. It is well known that two tuning forks produce beats even when one is held to each ear in such manner that a sound wave can not pass from one to the other through the air. Wundt thought that in this case the beats had their origin in the brain. Schaefer, however ("Zeitschrift für Psychologie und Physiologie

der Sinnesorgane "), regards the effect as due to conduction by the bones of the skull.

Residual Sensation.-Alfred M. Mayer ("American Journal of Science," January) has investigated the connection of the pitch of sounds with the length of their residual sensations—that is, with the sound perceived by the ear after actual vibration has ceased. The duration of the residual sound was measured by rotating perforated disks opposite the nipples of resonators that were sounded by tuning forks and noticing at what speed of rotation the interrupted sound seemed to become continuous. The duration was less the higher the pitch, varying from 00231 second for a frequency of 128 to 0.0049 second for a frequency of 1,024.

Minimum of Audibility.-Lord Rayleigh ("Philosophical Magazine," September), in experiments to determine the minimum current audible in the telephone, finds that the maximum sensitiveness to currents occurs in the region of frequency 640, where a current of 44 X 10-8 ampères produced an audible sound. Telephones varied greatly in sensitiveness. The same writer (ibid., October), in experiments on the amplitude of just audible aërial waves, finds that for a frequency of 256 this amplitude is about 1.27 X 10-7 centimetres.

Light. Luminosity.-P. Glan (Wiedemann's "Annalen," March) finds that the ratio of the volume of a candle flame to its illuminating power is very nearly constant, the difference between the actual luminosity and that calculated from this ratio being never greater than 3 per cent. Equal volumes of the bright flame of any two candles thus give the same amount of light.

Reflection.-W. Wernicke (Wiedemann's " Annalen," March) shows that when light is reflected from a silver film between two transparent media, the anterior of which has the higher refractive index, there is not only a normal acceleration of phase increasing continuously from zero toor of a wave length as the thickness of the silver increases from zero to opacity, but also an anomalous retardation, which shows itself when there are traces of another substance between the silver and the front medium, and which may amount to between and of a wave length.

Absorption.-G. B. Rizzo (Turin Academy) finds that Kirchhoff's law connecting the absorptive and emissive powers of substances does not hold good for cobalt glass. While its emissive power decreases nearly uniformly between wave lengths 685 and 580, the absorptive power shows decided maxima in the red, yellow, and green, that have no relation whatever to the emission.

Dispersion.-H. Rubens (Wiedemann's “Annalen," October) finds that Helmholtz's electromagnetic theory of dispersion accords with results obtained for fluorspar, quartz, rock salt, sylvine, and one of the heavy Jena silicate flint glasses over the region of the spectrum that was investigated-54 octaves.

Photometry.-J. B. Spurge (London Physical Society, Jan. 26) employs a photometric method in which two diffusing screens, illuminated respectively by the lights to be compared, are used as secondary sources, and the luminosities of the

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