Laivs of Molecular Force. 

 Table III. — Carbonic Dioxide. 



217 



V. 



Rv/O). 



v 2 <t>(v). 



v. 



TdLvfiv). 



v 2 <p(v). 



Perfect gas. 



1-421 





2-64 



2-56 



1661 



734 



1-92 



2159 



2-35 



264 



1566 



(7-00) 



(2-11) 



(2500) 



2-05 



2-77 



1482 



5-14 



2-13 



2071 



1 91 



2-86 



1441 



(5-00) 



(2-37) 



(2400) 



1-76 



3-02 



1430 



367 



2-31 



1858 j 









(The bracketed numbers are introduced from Andrews.) 



A glance at this Table shows the same facts to be in it as 

 in Table I. The critical volume of C0 2 is somewhere about 2; 

 and we notice that near this volume ~Rvf(v) tends to double 

 the value 1*421 in the gaseous state, while at the same point 

 v 2 <f>(v) approaches a constant value about the half of what 

 must from inspection be estimated as the upper limit of it. 

 Both functions are accurately represented by the same forms 

 as in the case of ethyl oxide with &= 1*762 and Z = 2773. 

 With these values the folio wing pressures were calculated for 

 comparison with experiment : — 





Table IV.— 



Carbonic D 



Ioxide 



• 









Volume 



11-74. 



8-8. 



5-87. 



3-67. 



2-64. 



2-20. 





100° 0. | 

 70° C. | 

 35° C. | 



Pressure, experiment. 

 Pressure, calculated. 



Pressure, experiment. 

 Pressure, calculated. 



Pressure, experiment. 

 Pressure, calculated. 



39 

 39-4 



34-5 



34-8. 



29-7 

 29-5 



49-8 

 50-4 



43-7 

 440 



36-5 

 36-5 



69 

 70 



58-8 

 59-4 



46-4 

 47 



96-8 

 99 



79-5 

 80-0 



55=8 

 57*5 



124 



123 



95 

 94 



61 

 60 



143 



137 



105 

 100 



63-6 

 577 



The agreement is quite satisfactory except at the lowest 

 volume, which is near the critical ; and I have shown (Phil. 

 Mag. August 1887) that near the critical point in capillary 

 tubes the relation of pressure to volume becomes fickle, the 

 measurements of Andrews and Amagat differing from one 

 another as much as experiment and calculation in Table IV. 

 To illustrate this at higher volumes I introduced into Table III. 

 a couple of Andrews's values of Jxvf(v) and v 2 (j>(v), from values 

 of Bf(v) and <j>(y) calculated by Ramsay and Young (Phil. 

 Mag. 1887), after conversion of Andrews's air-manometer 

 indications to true metres of mercury. It will be seen that 



Phil. Mag. S. 5. Vol. 35. No. 214. March 1893. Q 



