( 7B3 ) 



was followed. As practically the temperature for every individual 

 determination of the temperature might be considered as constant 

 (see § 1), a number of paris of isotherms could be immediately 

 obtained for every series separately. As they at the same time refer 

 to about the same densities, an accurate value may be derived for 



djpvA ) " 



from the graphical representation of pv \ on — . The 



I, I' A 'M 



temperatures in the different series nol differing more than 0.°2, the 

 results could be reduced to one and the same standard-temperature 

 in this way without the slightest difficulty. As standard-temperatures 

 were assumed the temperatures — 103°.57 and —135°. 71 of series 

 I, -182°.81 and -195°.27 of series II and —204°. 70, — 212°.82 

 and — 217°. 41 of series III. In the subjoined table the values of 



pv.-ii" pi' [('\ 



— — - j are given, which served for the reduction of the 



remaining determinations of the isotherms to these standard tem- 

 peratures t s , which relate to the hydrogen-thermometer at constant 

 volume and 1100 mM. pressure at 0°. 



From these mean coefficients values for 



'd (pv A ) 

 dt 



could be derived 



for the different points of \\\v respective isotherms, which for the 

 isotherm of — 212°. 82 have been given in Table XI of $ 10. 



§ 9. Survey of a determination. 



As an instance of determinations of isotherms at low temperatures 



we give here one of the measurements from the i 3 rd series at a density 

 326 times the normal, in oxygen boiling under strongly reduced 

 pressure. 



52* 



