Sparking-Potentials  in  Carton  dioxide  and  Nitrogen.      537 
apparatus  used.  In  order  to  determine  ft  in  these  cases  it 
would  be  necessary  to  have  an  apparatus  which  admitted  of 
larger  distances  between  the  plates.  When  j3  is  small  the 
formula 
Q-/3)€(a-gM 
reduces  to  n  =  n0ead.  When  the  sparking- distance  a  was 
more  than  1*2  cm.,  it  was  not  possible  to  determine  the 
spai  king-potential,  since  the  plates  could  not  be  separated 
by  more  than  that  amount. 
Carbon  dioxide. 
Pressure  2  rams. 
d -1 
I 
•2 
•3 
X=1400        q  8-32 
70-7 
747 
5=22       „  !          8-32 
71-7 
755 
/3=-0085 
a  =  -369.  Xa=516.  V=517. 
Pressure  1  mm. 
cl  
•2 
•3 
•4 
•5 
•6 
X=7J)0 
a  
8-54 
24-7 
73-1 
226 
787 
a  =10-68 
/3=-0041 
n  
8-54 
24-8 
73-8 
228 
790 
a=-7< 
Xa=515.  V=509. 
Pressure  1  mm. 
d 
•2 
•3 
•4 
•5 
X-875           q  
10-7 
36-1 
129 
643 
a  =11-83 
107 
36 
130 
645 
j8  =-0138          ••" 
a  =  -571.  Xa=500.  V=495. 
Phil.  Mag.  S.  6.  Vol.  11.  No.  64.  April  190(5. 
2N 
