578 SCIENTIFIC RECOUD POfc 1883. 



tained at a constant temperature below the fusing point After an hour 

 solidification was induced by contact with a fragment of solid phos- 

 phorus, the time being chronographically recorded. The progress of the 

 solidification is readily observed, the colorless and transparent liquid 

 becoming opaque. At the instant the opacity reaches the end of the 

 column another chronographic record is made. Where the solidification 

 is very rapid a tuning-fork chronograph is necessary. The author finds, 

 (I) that the duration of solidification is uniform for equal lengths of 

 column ; (2) that the velocity of solidification is independent of the tem- 

 perature at which the phosphorus has been melted; and (3) that this 

 velocity increases from l mm .G per second at 43°.8, to 353 mm .35. per sec- 

 ond at 36°, and 1030 mm .7 at 24°.9. (Jour. Phys., April, 1883, II, n, 159.) 



Wiedemann has modified the ordinary pyknometer by attaching to 

 it by a ground joint a tube with a lateral funnel for attaching it to a 

 mercury pump. After weighing the bottle and the stopper separately 

 they are put together, connected with the exhaust tube, exhausted, 

 filled with water from the funnel, freshly boiled, and weighed. The 

 powder is then introduced and the operation is repeated. The results 

 agree to the third decimal place. (Wied. Ann., xvn, 983; Phil. Mag., 

 May, 1883, V, xv, 369.) 



Decharme has continued his hydrodynamic experiments, and has suc- 

 ceeded in imitating by means of liquid or gaseous currents various 

 physical effects produced by electricity or magnetism ; such, for example, 

 as Nobili's rings, magnetic spectra, stratification of the electric discharge, 

 projection of a metallic wire volatilized by an electric discharge, Lich- 

 tenberg's figures, &c. He observes that aspiration corresponds to posi- 

 tive electrification in its effects, and a blast to negative. (Ann. Ghim. 

 Phys., February, July, 1883, V, xxvm, 198; xxix, 404.) 



Pfaundler has observed the explosion of a glass tube filled with liquid 

 carbon dioxide, the lower portion of which was immersed in a mixture 

 of solid C0 2 aud echer, and contained crystallized C0 2 . The tube had 

 frequently been exposed to a temperature of 31°. It is supposed 

 that the tube had been made brittle by the low temperature, though 

 Daguenet thinks it more probable that the expansion of the solid crys- 

 talline mass fractured the tube. Pfaundler has called attention also 

 to the explosion of a zinc gasometer which had contained oxygen for 

 six months, when a lighted taper was used to test the gas. It is sup 

 posed that the water in the tank had absorbed acid vapor from the 

 laboratory, and that these acted on the zinc, generating hydrogen within 

 the gasometer. ( Wied. Ann., xvn, 170, 175; J. Phys., April, 1883, II, 

 II, 191.) 



3. Of Gases. 



Terquem demonstrates the law of Archimedes for gases by suspending 

 a glass balloon in a bell jar by means of a silk filament passing through 

 the neck, the balloon being supported on one arm of a hydrostatic bal- 





