Am.  Joui.  Pharm. 
November,  1910. 
J       The  Netherlands  Pharmacopoeia.  525 
maceration  may  be  used.  When  maceration  is  followed,  the  com- 
minuted drug  is  mixed  with  the  proper  quantity  of  the  menstruum, 
allowed  to  macerate  five  days  with  occasional  agitation,  and  pro- 
tected from  light.  The  marc  is  pressed  out  and  the  liquid  portion 
allowed  to  stand  in  a  cool  place  for  two  days,  when  it  is  filtered, 
care  being  taken  to  prevent  evaporation.  In  following  out  the  per- 
colation method  the  menstruum  is  divided  into  three  parts,  two 
of  which  are  intimately  mixed  with  the  drug,  allowed  to  macerate 
for  twelve  hours.  This  macerated  mixture  is  then  added  to  a  per- 
colator and  slightly  compressed.  Sufficient  menstruum  is  added 
until  the  percolate  begins  to  flow  from  the  orifice  of  the  percolator, 
the  latter  is  then  closed  and  the  drug  allowed  to  macerate  for  24 
hours.  The  stopper  is  removed  and  percolation  allowed  to  proceed, 
and  as  much  menstruum  added  as  is  necessary  to  make  the  required 
amount  after  expression  of  the  marc.  The  tincture  is  allowed  to 
stand  for  two  days  in  a  cool  place,  when  it  is  filtered,  taking  care 
to  avoid  loss  by  evaporation. 
All  of  the  tinctures  of  potent  drugs  are  made  by  percolation, 
while  all  of  the  remaining  tinctures  are  made  by  maceration.  In 
the  case  of  tinctura  secalis  cornuti  and  tinctura  strychni,  the  fixed 
oil  is  first  removed  from  the  drugs  by  means  of  petroleum  ether. 
There  is  also  a  general  test  given  for  the  detection  of  wood  alcohol 
and  acetone  in  tinctures. 
Three  classes  of  extracts  of  vegetable  drugs  are  recognized : 
dry  extracts  or  siccum  (extracta  sicca),  which  contain  not  more 
than  6  per  cent,  of  moisture ;  solid  extracts,  or  extracta  spissa,  which 
contain  not  more  than  20  per  cent,  of  water,  and  liquid  extracts. 
The  extracts  of  potent  drugs  are  made  by  percolation  in  much  the 
same  manner  as  given  for  tinctures,  the  alcohol  being  removed 
either  by  distillation  at  a  temperature  not  higher  than  90 0  C,  or  it 
may  be  allowed  to  evaporate  spontaneously  until  the  extract  has 
the  desired  consistency.  Most  of  the  extracts  of  the  other  drugs  are 
made  by  maceration  or  infusion,  it  being  understood  that  the  proc- 
esses are  carried  out  at  definite  temperatures,  considerable  care 
being  directed  in  the  evaporation  of  the  extracts.  In  extractum 
secale  cornuti,  chloroform  is  used  as  a  menstruum ;  in  a  number 
of  extracts  a  certain  amount  of  glycerin  is  directed,  as  with  cin- 
chona. With  the  latter  drug  dilute  hydrochloric  acid  forms  a  part 
of  the  menstruum.  In  preparation  of  the  liquid  extract  of  hydrastis 
tartaric  acid  is  added  to  the  menstruum.  Methods  are  given  for  the 
determination  of  moisture,  the  examination  of  the  ash  for  metallic 
