144 Proceedings of the Royal Physical Society. 



spheroidal lining would cease when the pressure increased, in 

 a manner similar to the stoppage of vapour or steam from 

 water at 212°, when the atmospheric pressure is increased. 

 The distance between the central nucleus and the crust of 

 the globe will be determined by the temperature of the 

 nucleus, as the higher the temperature of the heated centre, 

 then the further off will it repel or keep off the crust. Dr 

 Macadam was still of opinion, that the only satisfactory 

 theory which accounted for the compatibility of a cold sur- 

 face and a highly ignited central nucleus was based upon the 

 spheroidal condition of matter. The same theory, applied 

 to the Geysers of Iceland, accounted for the discharge of hot 

 water from these intermittent hot springs. 



Dr Wright, in reply, stated that Dr Macadam was mis- 

 taken in supposing that the plate on which Dr Wright per- 

 formed his experiments was heated too highly ; and this he 

 showed to be the case by turning off the gas from the appa- 

 ratus, when the water floating on the plate instantly came 

 in contact with the latter, and exploded. It was not true 

 that bodies in the so-called spheroidal state totally reflected 

 heat. So far from that, they invariably became heated ; and 

 solids such as camphor floated on the plate until they became 

 quickly entirely liquefied, and converted into vapour. It 

 was also incorrect to say that the distance between the 

 spheroid and the plate bore any relation to the heat of the 

 plate. He found that after a certain distance had been 

 attained,, a further increase of heat was not attended with 

 any effect. He maintained that temperature had really no 

 essential relation to the spheroid state ; that the whole 

 phenomena depended entirely upon the adhesion of vapour 

 to the surface of the spheroidal body, and could be shown 

 in various liquids, such as solutions of soap, alcohol, albumen, 

 essential oils, &c, perfectly well when they were in the 

 cold state. 



