Am.  Jour.  Pharm. ) 
Sept.,  1883.  ) 
Examination  of  Quinine  Pills. 
435 
There  was  a  loss  of  1*328  part  for  each  100  parts  of  the  salt 
employed,  which  gives  for  each  10  grains  of  quinine  sulphate  used  a 
loss  of  0*1328  grains;  or,  instead  of  7*4312  grains,  only  7*2984  grains 
of  pure  quinine  were  obtained. 
In  a  letter  dated  Wiesbaden,  March  10,  1882,  Professor  Dr.  R. 
Fresenius  speaks  of  this  method  as  follows : 
(Translation.)  "  In  order  to  form  a  definite  opinion  on  your 
method  for  the  determination  of  sulphate  of  quinine,  I  have  made 
several  experiments.  I  have  first  employed  pure  sulphate  of  quinine, 
and  obtained  by  your  method  the  following  figures : 
Sulphate  of  quinine  used.  Found. 
1.  0-1250  gm.  0-1254  gm. 
2.  0-1440  0-1448  " 
"  For  determining  the  influence  of  sugar  and  gum,  the  sulphate  of 
quinine  was  mixed  with  equal  weights  of  the  bodies  named,  when  the 
results,  according  to  your  method,  were  as  follows  : 
Sulphate  of  quinine  used.  Found. 
1.  0-1282  0-1260 
2.  0-1348  0-1335 
3.  0-1268  0-1248 
"  I  will  not  omit  to  direct  attention  to  the  necessity,  in  the  presence 
of  a  considerable  proportion  of  gum,  of  very  carefully  triturating  the 
mass  which  has  been  dried  with  the  lime,  and  of  extracting  it  very 
frequently  with  chloroform.  In  other  respects  I  can  only  confirm  that 
the  method  adopted  by  you  will  yield  quite  useful  results." 
Second  Method. — The  loss  by  the  above  method  was  considered  to 
be  too  great,  and  for  this  reason  the  following  procedure  was  adopted : 
The  pills  are  rubbed  into  a  smooth  paste  with  a  little  water,  2  drops 
of  diluted  sulphuric  acid  being  added  for  each  grain  of  quinine  sul- 
phate. A  quantity  of  recently  slaked  lime  equal  to  three  times  the 
weight  of  the  pills  is  well  mixed  with  the  paste ;  then  the  same  weight 
of  well-washed  and  dried  fine  sand  is  added  ;  the  whole  is  thoroughly 
triturated  and  dried  at  a  moderate  heat,  when  it  can  be  easily  pow- 
dered and  readily  removed  from  the  mortar  without  loss.  The  fine 
powder  thus  obtained  is  placed  in  a  small  glass  percolator,  which  is 
fixed  to  an  accurately  tared  flask  by  means  of  a  twice  perforated  cork. 
The  percolator  is  connected  with  a  back-flow  cooler,  or  reversed  con- 
denser, such  as  is  used  in  plant  analysis,  and  which  has  often  been 
