^mAP°rii;i9oiarm'}    Recent  Literature  Relating  to  Pharmacy.  191 
VOLUMETRIC  METHODS  OF  THE  NEW  GERMAN  PHARMACOPCEIA. 
Of  the  three  methods  of  volumetric  analysis,  acidimetry  or 
alkalimetry  is  employed  in  the  new  German  standard  for  the  estima- 
tion of  not  only  the  usual  inorganic  chemicals,  but  also  in  the 
estimation  of  such  alkaloidal  drugs  as  pomegranate  bark,  ipecac, 
aconite,  nux  vomica  and  its  preparations,  belladonna,  cinchona, 
hyoscyamus  and  their  preparations;  also  for  balsam  of  Peru,  bal- 
sam of  Tolu,  copaiba,  rosin,  wax,  cod  liver  oil  and  oil  of  lavender. 
The  oxidation  analysis  includes  the  well-known  chemicals  such 
as  iron  salts,  chlorine  water  and  iodine,  and  through  the  latter  it  is 
applied  to  the  iodine  absorption  estimation  of  fats.  The  precipita- 
tion volumetric  analysis  is  directed  for  the  same  chemicals  as  in 
the  U.S.P.  and  also  for  the  assay  of  bitter  almond  water  and  the 
mustard  oils.  Concerning  the  estimations  of  the  first  class,  that 
for  the  alkaloids  is  practically  the  same  as  in  the  U.S. P.,  a  possible 
exception  being  that  "  jodeosin  "  is  recommended  as  an  indicator; 
always,  however,  with  the  addition  of  an  ethereal  layer.  For  the 
cinchona  alkaloids,  hsematoxylin  is  preferred. 
The  estimation  of  acid  number,  ester  number,  and  saponification 
number  of  oils  and  balsams  is  performed  by  treating  the  substance 
with  semi-normal  alcoholic  potassa  titration  of  excess  with  semi- 
normal  hydrochloric  acid,  phenolphtalein  being  used  as  indicator. 
The  approximate  details  of  such  estimation  can  be  lound  in  litera- 
ture, notably  Proceedings  of  the  American  Pharmaceutical  Associa- 
tion, so  suffice  it  here  to  state  the  following  standards  are  chosen 
by  the  German  authority : 
Acid  Number.      Ester  Number.      Saponification  Number. 
Balsam  Peru                       —  132*5  224-6 
Balsam  Tolu  ii2'3-i68'5  22,4-78"4  — 
Copaiba  75 -6-1797  —  — 
Wax  18*5-  24-1  72'8-75'6  .  — 
Oil  lavender                      —  84  — 
Cod  liver  oil                      —  —  196*6 
The  iodine  absorption  of  fats  is  estimated  by  addition  of  the  fat 
to  an  87  per  cent,  alcohol  containing  mercuric  chloride  and  a 
definite  quantity  of  iodine ;  the  mixture  is  allowed  to  stand  forty- 
eight  hours  and  the  unabsorbed  iodine  is  estimated  by  titration 
with  decinormal  sodium  thiosulphate.  Chloroform  is  added  to  the 
mixture  for  purpose  of  clearing,  this  aiding  in  obtaining  accurate 
