LOKI) RAYLEIOH ON THE COMPRESSIBILITY OF GASKs 



The experiments on carlxmic anhydride and on nitrons oxide were of later date, 

 having heen postponed until the apparatus had l>een well tested on other gases. 



In both these cases it was found that the readings were less constant than usual, 

 signs being apparent of condensation upon the walls of the containing vessels, or 

 possibly upon the cement in the manometer. Under these circumstances it seemed 

 desirable to avoid protracted observations and to concentrate effort upon reproducing 

 the conditions (especially as regards time) as closely as possible with and without the 

 use of the large bulbs. In this way, for example, the question of the cement is 

 eliminated. Condensation upon the walls of the large bulbs themselves, if it occurs, 

 cannot be eliminated from the results ; all that we can do is not unnecessarily to 

 increase the opportunity for it by allowing too long a time. It is certain that, unless 

 by chance, these results are less accurate than for the other gases, i.e., less accurate 

 absolutely, but the value of a is so much larger that in a sense the loss of accuracy is 

 less important. Two entirely independent results for nitrous oxide agreed well. 

 They were : 



November 22, 26, 1904 . 

 23, 29, 1904 . 



B= 1-003295 

 6=1-003252 



Mean . 



1-00327 



The gas was from the same supply as had been used for density determinations. 



In applying these results to correct the ratios of densities as observed at 

 atmospheric pressure to what would correspond to infinite rarefaction, we have, 

 taking oxygen as a standard, to introduce the factor (l-|-a)/(l-|-a ), a<) being the 

 value for oxygen. Taking a from the third column, which may be considered without 

 much error to correspond to a temperature of 13 C. throughout, and also from the 

 fifth column, we have : 



The double of the first number in the second column, viz., 2 '00256, represents, 

 according to AVOGADRO'S law, the volume of hydrogen which combines with one 

 volume of oxysren to form water, the pressure being atmospheric and the temperature 

 13 C. SCOTT gave 2'00245 for 16 C. In his later work MOKLEY found 2'0027, but 



