486 
Laboratory  Notes, 
(  Am.  Jour.  Pharro, 
1      Oct.,  1877. 
equivalent  to  17*5  per  cent,  of  quinia  trihydrate,  no  waste  of  quinia 
being  considered.  The  water  lost  by  citrate  of  iron  and  quinia  on 
the  steam-bath,  in  attaining  a  constant  weight,  was  found  by  Mr.  Hol- 
loway,  for  four  samples,  respectively  at  9*2,  4*2,  8*1  and  6'8  per  cent. 
A  sample  prepared  according  to  the  Pharmacopoeia  (not  "  soluble  "), 
when  recent,  was  found  to  lose  12*5  per  cent,  on  the  steam-bath.  But 
whether  any  combined  water  is  retained  on  the  steam-bath  or  not,  I  do 
not  know.  The  mean  of  the  five  samples  above  given  is  8*4  per  cent, 
loss  on  the  steam-bath.  The  proportion  of  quinia  by  calculation  from 
the  materials,  assuming  8  per  cent,  of  water  (with  normal  ferric  citrate) 
would  be  13*9  per  cent,  of  anhydrous  quinia,  or  l6"2  per  cent,  of  quinia 
trihydrate.  Two  samples  of  quinia  iron  citrate,  made  by  Mr.  Hollo- 
way  (without  precipitating  the  alkaloid  from  its  sulphate,  and  with  addi- 
tion of  ammonia,  as  described  in  Note  VIII),  were  found  by  him  to 
contain  respectively  14*9  and  14*2  per  cent,  of  quinia,  as  dried  at 
2I2°F. 
The  British  Pharmacopoeia  requires  about  16  per  cent,  of  quinia, 
the  direction  being  to  dissolve  the  scales  in  water,  add  ua  slight  excess 
of  ammonia,"  the  precipitate,  "collected  on  a  filter  and  dried,"  to 
weigh  8  grains  for  50  of  the  scales.  The  British  preparation  takes 
1  part  of  quinia  sulphate  to  3  parts  of  citric  acid,  the  United  States 
preparation  takes  1  part  of  quinia  sulphate  to  3*6  parts  of  citric  acid. 
VIII.   The  Pharmacopceial  Preparation  of  Citrate  of  Iron  and 
Quinia. 
The  preparation  strictly  according  to  the  United  States  Pharmacopoeia 
not  being  a  u  soluble  citrate,"  is  not  in  use  and  not  under  discussion. 
Any  scale  citrate  in  favor  must  be  a  "soluble  citrate,"  i.  e.,  an  am- 
monio-citrate,  and  probably  all  or  nearly  all  the  citrate  of  iron  and  quinia 
manufactured  is  made  on  the  basis  of  some  sort  of  citrate  of  iron  and 
ammonium,  with  addition  of  quinia  (or  quinia  sulphate).  In  the  United 
States  citrate  of  iron  and  ammonium,  normal  ferric  citrate  solution  is 
treated  with  enough  ammonia  to  saturate  38  per  cent,  of  the  citric  acid 
from  which  the  ferric  citrate  was  made.  In  the  British  citrate  of  iron 
and  quinia,  an  acid  solution  of  ferric  citrate  is  treated  with  sufficient 
ammonia  to  neutralize  20  per  cent,  of  the  citric  acid,  and  also  with 
quinia  enough  to  neutralize  about  4  per  cent,  of  the  citric  acid.  The 
German  "  Chinium  ferro-citricum "  consists  only  of  normal  ferrous 
