1887.] for the Change of State from Liquid to Gas. 



223 







2 Cr U coed point. ■ ,. f^0}* \ {' 



I 





c? 



V 



V 



1 



; 



| Aoris of vo2wn.es. \ 



if. 

 I 



p 



Sy^Vf-tp o ur y?; -ess u r'e title ■for' Isotherm**-* 

 VorpoTt.r' pressure fine, .for Jsoth cr/i) a I 110 '(." j 





£&ct/ tneed of.t V— 206 



O ! 

 1 \ 



/ 



%%%*T'hc fine/ex tire jianci&olie branch (t e ; 

 tn this region but; the highest point 

 even for critical Isothcrm-ool ts — 2.700 . 



1 \ Sw 

 j fi/jJcr&olic\\~e(jcttri'c ij-cateh 



' of Tsothe?/i\iI J'or £07 C. n 





sc faro me<e£ a/: —£46 at tjre povn.l 1 on tht 9 



■ ■■ J^ot/iC TJ/LOtf 



from the origin compared with the dimensions of the serpentine part 

 of the positive branch, so that it is not easy to represent them both in 

 the same figure. I have calculated several points on the isothermals 

 corresponding to 110° C, 207-5° C, and 243-5° C. 207'5° C. is the 

 isothermal that just touches y = 0, while 243'5° C, is the critical iso- 

 thermal. The dotted lines represent the saturated vaponr-tensions for 

 which the areas included in the loops of the curve above and below are 

 equal. The points numbered 1, 2, 3, 4 are specially noticeable points 

 on the curves so numbered in the general feature diagrams. 



The isothermal 110° C. goes down at the point 1 entirely outside the 

 diagram to a pressure of —246,800 mm., and intersects its vapour- 

 pressure line outside the diagram to the right at a volume of 206. 

 The negative parabolic branch of this isothermal only comes up at 

 the point 3 to a pressure of —4,442,000 mm., while the corresponding 

 points of 207-5° C. and 243-5° C. come only to -4,044,000 mm. and 

 — 2,743,000 mm., so that they are very far off. In the isothermal 

 207-5° C. the point 4 lies at about x = -32, p = -32,000, so that it 

 is not very far off. 



What strikes me as most remarkable about these curves and other 



