316 QUARTERLY JOURNAL. 



EXTRACTS 



FROM 



FOREIGN AND DOMESTIC JOURNALS. 



[ Frrm the London Athensum.] 



TRANSACTIONS OF THE BRITISH ASSOCIATION FOR 

 THE ADVANCEMENT OF SCIENCE. 



CSIEHIISTRie^. 



Experiments on the spheroidal state of bodies, and. its application 

 to steam-boilers ; and on the freezing of water in red hot vessels. 

 By Prof. BouTiGNY. 



Prof. B. proceeded to show, that a drop of water projected upon 

 a red hot plate, does not touch it ; but that a repulsive action is ex- 

 erted between the plate and fluid, which keeps the latter in a state of 

 rapid vibration. At a wliite heat, this repulsive energy acts with the 

 greatest force, but ceases or becomes nothing at a brown-red heat. 

 The temperature of the water whilst in the spheroidal state, is found 

 to be only 96°, and this temperature is maintained so long as the 

 heat of the plate is kept up. To bring the water to a boiling point 

 (212°), it is necessary to cool the plate. These phenomena are ex- 

 plained by Prof. Boutigny, on the supposition that the sphere of 

 water has a perfect reflecting surface, and consequently that the 

 lieat of the incandescent plate is reflected back upon it ; and some 

 experiments have been made which show that this is the case, the 

 plate becoming visibly redder over those parts on which the vibrating 

 globule played. Several experiments were made in proof of this 

 necessary cooling, to produce ebullition. The red hotplate, with its 

 spheroidal drop, was renewed from the spirit lamp, and after a minute 

 or two, the water began to boil, and was rapidly dissipated in steam. 

 Ammonia and ether were shown, although exceedingly volatile, to 

 follow the same law. Iodine put upon the heated plate, became fluid, 

 and revolved in the same manner as other fluids, no vapors escaping 

 whilst the high temperature of the metal was maintained ; but when 

 allowed to cool to the point of dull redness, it was immediately dis- 

 sipated in violet vapors. The nitrate of ammonia fused on the glow- 

 ing hot plate, and vibrated with great energy ; but on cooling of ihe 

 plate, the salt entered into vivid combustion. The repulsive action 

 was shown by plunging a lump of silver, glowing at a red heat, into 

 water. As long as its bright redness remained, there was no ebulli- 



