Flames  containing  Salt  Vapours  for  Alternating  Currents.    491 
(2)    Variations  of  the  apparent  Capacity  with  the 
Concentration  and  Nature  of  the  Salt   Vapour. 
The  salt  solutions  sprayed  were  made  up  with  distilled 
water  and  pure  salts  carefully  dried.  We  shall  first  give 
a  few  examples  of  the  curves  obtained,  showing  the  relation 
between  the  distance  apart  of  the  condenser-plates  and  the 
galvanometer  deflexion,  from  which  curves  the  position  of 
the  minima  were  deduced.  Fig.  3  shows  several  such 
curves.     The  sharpness  of  the  minimum  was  usually  greater 
Fig-.  3. 
70 
90 
f 
v> 
i. 
// 
\ 
\ 
\ 
[/ 
\ 
5 
.         | 
12  3  tenths  of  an  inch. 
Distance  between  plates  of  Adjustable  Condenser. 
when  the  conductivity  was  large  and  the  distance  therefore 
small,  than  when  the  converse  was  the  case.  The  accuracy 
with  which  the  minimum  could  be  found  was  consequently 
nearly  the  same  for  large  as  for  small  conductivities. 
During  the  course  of  the  experiments  the  ratio  of  the  two 
condensers,  Cl5  C2,  was  changed  on  one  or  two  occasions. 
When  this  had  been  done,  some  of  the  observations  made 
before  the  change  were  repeated,  and  the  factors  required  to 
reduce  all  the  results  to  the  same  standard  so  determined. 
The  following  table  contains  the  results  obtained,  the  number 
of  alternations  per  second  being  32  x  10\  and  rf.=3'33  tenths 
of  an  inch. 
2  K  2 
