22± 



Mr. "William Sutherland on the 

 Table XL 





H, 



N 2 . 



2 . 



CH 4 . 



Air. 



Critical \ exper. . . . 

 Volume. [calc 



Critical fexper. ... 

 Temperature. ^ calc 



Critical f exper. . . . 

 Pressure. \ calc 



—229 



"lb 



3-4 

 3-96 



-146 

 -155 



27 

 25 



2-5 

 267 



-119 

 -127 



38 

 40 



-995 

 -95 



37 

 32 



-140 

 -149 



30 

 27 



The agreement is all that can be looked for in view of the 

 difficulties of measuring these low critical temperatures and 

 their associated pressures. With regard to lrydrogen all we 

 know is that Olszewski (Compt. Rend, ci.) has submitted it to 

 a temperature estimated by him as —220° without a sign of 

 liquefaction. If our equation is to be trusted, it would indi- 

 cate that he would need to go some 10 degrees lower before 

 the only unliquefied gas is conquered. Wroblewski has pub- 

 lished data on the compressibility of H 2 up to pressures of 70 

 atmospheres at temperatures of —103° and —182° (Journ, 

 Chem. Soc. 1839), and with these our equation is in accord, 

 but there is hardly need of tabulated proof. 



3. Brief discussion of exceptional Compounds such as the 

 Alcohols and Ethylene. — To complete our survey of the ex- 

 perimental material on bodies above the critical region we 

 have to consider Hamsny and Young's observations on methyl 

 and ethyl alcohol, and Amagat's on ethylene. Ramsay and 

 Young point out that at low volumes the values of ^5pfaT for 

 the alcohols are not so reliable as for ethyl oxide, being deter- 

 mined from a smaller temperature range ; hence our values of 

 Hvf(v) and v 2 (p{v) are not so reliable as before, but they 

 suffice to show the exceptional nature of these bodies. 



Table XII.— Methyl Alcohol. 



! »- 



Rvf{v). 



ttyv). 



v. 



Bufa). 



v^{v). 



Perfect gas. 



1-950 





25 



350 



24S00 



340 



214 





20 



3-70 



23000 



240 



2-32 



45500 



18 



379 



22000 



200 



2-40 



48000 



16 



3-97 



21700 



170 



2-46 



46100 



14 



4-18 



20900 



135 



256 



43700 J 



12 



438 



19900 



100 



270 



41000 



11 



4-46 



19C0O 



70 



3-04 



42100 



10 



453 



17900 



50 



3-10 



33500 



9 



4-58 



16700 



40 



3-20 



30200 



8 



455 



15000 



30 



3-37 



26800 ' 



7 



439 



12900 





