no 



On the Liquefaction and Solidification [1844. 



vapour over it at the temperature of 86 Fahr., and the former 

 is little more than twice that of the latter ; hence a few degrees 

 more of temperature would bring them together, and Brunei's 

 result seems to imply that the state was then on, but in that 

 case Addams's results could only be accounted for by supposing 

 that there was a deficiency of carbonic acid. The following 

 are the pressures which I have recently obtained : 



Carbonic acid is remarkable amongst bodies for the high 

 tension of the vapour which it gives off whilst in the solid or 

 glacial state. There is no other substance which at all comes 

 near it in this respect, and it causes an inversion of what in all 

 other cases is the natural order of events. Thus, if, as is the 

 case with water, ether, mercury or any other fluid, that tem- 

 perature at which carbonic acid gives off vapour equal in 

 elastic force to one atmosphere, be called its boiling-point ; or, 

 if (to produce the actual effect of ebullition) the carbonic acid 

 be plunged below the surface of alcohol or ether, then we 

 shall perceive that the freezing and boiling points are inverted, 

 i. e. that the freezing-point is the hotter, and the boiling-point 

 the colder of the two, the latter being about 50 below the 

 former. 



Euchlorine. This substance was easily converted from the 

 gaseous state into a solid crystalline body, which, by a little 

 increase of temperature, melted into an orange-red fluid, and 

 by diminution of temperature again congealed ; the solid eu- 

 chlorine had the colour and general appearance of bichromate 

 of potassa; it was moderately hard, brittle and translucent; 

 and the crystals were perfectly clear. It melted at the tempe- 



