458 



On the Gaseous State of Matter. 



[Apr. 27, 



p- 



f=Q°-5, 



P* 



^'=64°, 



p. 



*'=100°, 





€. 





e - 





e. 



12-01 



1 



12-95 



17-60 



i 



18-57 



20-17 



1 



20-98 



13-22 



1 



T¥si 

 l 



16-13 



1 

 19-12 



20-36 



1 



2T65 



1 

 24-18 



1 

 27-08 



1 

 30-64 



1 

 34-67 



_I_ 



39-08 



1 

 46-34 



1 



54-57 

 1 



65-97 

 I 



22-37 



1 



23-35 



1 

 26-09 



1 

 29-32 



1 

 33-05 



1 

 37-09 



1 

 43-54 



1 

 50-63 



1 

 60-30 



1 



73-97 

 1 



14-68 

 17-09 



22-56 

 25-06 



24-85 

 27-76 



20-10 



1 



23 T 03 



28-07 



31-06 



22-26 



1 



25 7 96 



31-39 



34-57 



24-81 



1 

 2JF62 



34-92 



40-09 



2769 



1 



SlTol 



40-54, 



45-99 



31-06 



1 



39^59 



46-56 



53-81 



34-49 



1 



45-80 



54-33 



64-27 







64-96 



1 



80-25 



96-65 



1 







81-11 



iiFo 

 i 



105-69 



1 







106-88 



18F5 

 1 



145-44 



218 r 

 1 







145-54 



321F9 

 1 



223-57 



0791$ 







222-92 



446-4 







If we put |0=ep, and calc-ulate the values of p for each of the above 

 experiments, it will be found that these values diminish regularly as the 

 pressure increases at each temperature, with the exception of the last 

 observation at 64°, where the value of p is greater than at the preceding 

 observation. This change of direction in the value of p is explained by 

 the circumstance already mentioned, that the carbonic acid at the higher 

 pressure has been reduced to the liquid volume (although no liquefaction 

 has taken place) in passing through the conditions of matter intermediate 

 between the gaseous and liquid states. 



The relations between the volumetric curves in the ordinary gaseous 

 state for different temperatures are determined by means of what the 

 author calls the homologues or homologous points of those curves — that is, 

 the points in any two isothermals where the values of p are equal, or 



pvs=p'v\ .» ............. ; (A) 



Prom a careful analysis of the experiments described in this communi- 

 cation and in his former Bakerian Lecture, the author shows that the 

 ordinary gaseous state is characterized by the ratio of the external pres- 

 sures for all the homologues of any two given temperatures being con- 

 stant, or 



(B) 



5-m, 



