106 On the Liquefaction and Solidification [1844. 



rator such as that already described, and conducted into a 

 condensing tube under the generating pressure. The ordinary 

 carbonic acid bath did not condense it, but the application of 

 one cooled under the air-pump caused its liquefaction, and 

 fluoboron then appeared as a very limpid, colourless, clear fluid, 

 showing no signs of solidification, but when at the lowest tem- 

 perature mobile as hot ether. When the pressure was taken 

 off, or the temperature raised, it returned into the state of gas. 

 The following are some results of pressure all that I could 

 obtain with the liquid in my possession ; for, as the liquid is 

 light and the gas heavy, the former rapidly disappears in pro- 

 ducing the latter. They make no pretensions to accuracy, 

 and are given only for general information. 



Fahr. Atmospheres. 



-100 .. 4-61 

 - 82 7-5 



Fahr. Atmospheres. 



-72 . . 9-23 

 -66 . 10-00 



Fahr. Atmospheres. 



-62 . . 11-54 



The preceding are, as far as I am aware, new results of the 

 liquefaction and solidification of gases. I will now briefly add 

 such other information respecting solidification, pressure, &c., 

 as I have obtained with gaseous bodies previously condensed. 

 As to pressure, considerable irregularity often occurred, which 

 I cannot always refer to its true cause : sometimes a little of 

 the compressed gas would creep by the mercury in the gauge, 

 and increase the volume of enclosed air ; and this varied with 

 different substances, probably by some tendency which the 

 glass had to favour the condensation of one (by something 

 analogous to hygrometric action) more than another. But 

 even when the mercury returned to its place in the gauge, 

 there were anomalies which seemed to imply, that a substance, 

 supposed to be one, might be a mixture of two or more. It is, 

 of course, essential that the gauge be preserved at the same 

 temperature throughout the observations. 



Muriatic Acid. This substance did not freeze at the lowest 

 temperature to which I could attain. Liquid muriatic acid dis- 

 solves bitumen; the solution, liberated from pressure, boils, 

 giving off muriatic acid vapour, and the bitumen is left in a 

 solid frothy state, and probably altered, in some degree, che- 

 micallyi The acid unites with and softens the resinous cap 



