64 



Royal Society :- 



For higher pressures than 35 atmospheres a different unit volume 

 must be taken, on account of the liquefaction of the carbonic acid. 

 The next Table contains the values of a, referred to tJie unit volume 

 at 64°, between 64° and 100° at constant pressures up to 223 atmo- 

 spheres. 



p. 



a (64°-100°). 



2- 



* (64°-100°). 



17-09 



0-003572 



46-54 



0-004946 



20-10 



0-003657 



54-33 



0-005535 



22-26 



0-003808 



64-96 



0-006512 



24-81 



0-003892 



81-11 



0-008033 



27-69 



0-004008 



106-90 



0-013150 



31-06 



0-004187 



145-50 



0-018222 



34-49 



0-004266 



223-00 



0-008402 



40-54 



0-004596 







As the value of a changes with the temperatures, the coefficients 

 given above are average coefficients for the ranges of tempera- 

 ture specified. It will be observed that the value of a increases 

 with the pressure until a very high pressure is attained, when it 

 changes its direction and diminishes. This apparent anomaly de- 

 pends upon the carbonic acid at the high pressure having passed 

 from the gaseous state proper to the intermediate conditions, which 

 the author has formerly described as establishing a continuity be- 

 tween the gaseous and liquid states of matter. 



If we designate by a' the coefficient of elastic force when a gas 

 is heated under a constant volume, we shall have in the case of a 

 perfect (ideal) gas 



In the ordinary gaseous state the value of a' diverges widely at 

 high pressures from that of a, as will appear from the two follow- 

 iug Tables. In the first Table the values of a' are referred to a 

 unit pressure at 0°, and p is the initial pressure in atmospheres. 



p- 



*' (0°-6°-5). 



«' (0°-64°). 



«' (64°-l00°). 



16-42 

 21-48 

 25-87 

 30-37 

 33-53 



6-00537 



0-00588 



6-00734 



0-004754 

 0-005237 

 0-005728 

 0-006357 

 0-006973 



0-004607 

 0-004966 

 0-005406 

 0-005861 

 0-006334 



In the next Table the value of a! between 64° and 100° referred 

 to a unit pressure at 64° is given for a large range of pressure. 

 Both the initial and final pressures are given. 



