402  EXAMINATION  OF  THE  SULPHATE  OF  QUINIA. 
cipitate  were  then  added  to  this  ash  in  the  crucible,  and  the 
whole  was  well  ignited,  cooled  over  sulphuric  acid  and  weighed. 
The  net  yield  of  BaO,  S03,  was  14686  gram. 
Then,  as  116-7  =eq.  of  BaO,  S03,  ;40=eq.  of  S03,  :: 
14686  gram.  BaO,S03,  :  -5033  gram.  S03=the  amount  of  acid 
obtained. 
♦  Then  4-0702  gram,  of  base+-5033  gram,  of  acid,==  45735 
gram.,  which  leaves  4265  gram,  as  the  quantity  of  water,  held 
by  the  5  gram,  of  effloresced  commercial  salt,  or  8.53  per  cent. 
But  the  acid  and  base  are  not  in  the  equivalent  proportions  for 
disulphate  of  quinia,  the  acid  being  478  per  cent,  in  excess. 
Showing  either  free  acid,  a  portion  of  neutral  salt  of  quinia,  or 
some  foreign  base  of  higher  saturating  power. 
Experiment  JVo.Q. 
The  same  quantities  of  the  pure  effloresced  sulphate,  as  in  ex- 
periment No.  4,  were  weighed  off  at  the  same  time,  and  marked 
C  and  D.  Portion  C  was  treated  precisely  like  portion  A,  in 
every  practicable  respect,  and  yielded  a  net  fused  precipitate  of 
4.2536  gram.,  or  4.506  per  cent,  more  of  base. 
Experiment  No.  7. 
Portion  D  was  treated  precisely  like  portion  B  in  every  prac- 
ticable respect,  and  yielded  a  net  ignited  precipitate  of  1.4706 
gram.  BaO,  S03  =.50406  gram.  S03=the  amount  obtained. 
Then  4.2536  gram,  of  base  -f  .50406  gram,  of  acid  =4.75766 
gram,  as  the  yield  obtained  from  5.  gram,  of  the  salt,  leaving 
only  .24234  gram.,  or  4.847  per  cent,  of  water,  present  in  this 
effloresced  salt.  But  on  being  heated  to  242°  without  having 
fused,  this  very  identical  10  gram,  of  salt  lost  4.577  per  cent, 
of  its  weight ;  and  this  would  indicate  that  when  thus  heated  it 
could  have  contained  only  .27  per  cent,  of  water  of  crystallization. 
The  acid  and  base  are  not  in  the  equivalent  proportion  for 
disulphate  of  quinia;  but  instead  of  there  being  an  excess  of 
acid,  as  in  Experiments  No.  4  and  5,  there  is  here  an  excess  of 
base,  or,  in  other  words,  a  deficiency  of  acid  of  .4025  per  cent. 
In  obtaining  these  results  every  known  source  of  error  was 
avoided ;  and  they  were  all  verified  by  repetition,  but  by  the 
same  method  of  proceeding.  The  time  necessary  for  further 
research  to  elucidate  the  discrepancies,  is  not  at  present  at  my 
