SYRUPUS  SENEGA. 
47 
same  characters.    It  crystallizes,  owing  to  the  presence  of  a 
little  alcohol. 
IX.  Syrup  prepared  July,  1867,  like  VII,  differing  only  in 
the  application  of  boiling  alcohol  to  exhaust  the  aqueous  ex- 
tract and  immediate  filtration  from  undissolved  portions.  In 
appearance  and  properties  same  as  VII. 
X.  Syrup  prepared  June,  1867,  like  VII,  differing  in  the  use 
of  diluted  alcohol  for  the  exhaustion  of  the  root,  and  of  boiling 
alcohol  for  the  exhaustion  of  the  extract.  This  preparation  was 
not  clear,  and  in  fact  resembled  in  appearance  and  properties  I, 
but  was  not  quite  so  aromatic. 
XI.  Syrup  prepared  July,  1867,  like  X,  with  which  it  corres- 
ponds in  every  respect. 
Syrups  I,  IV  and  V  were  prepared  from  the  same  lot  of  root ; 
III,  VI  and  VII  from  a  second,  IX  and  XI  from  a  third,  and 
the  others  from  individual  lots. 
Portions  of  each  lot  accompany  this  paper. 
It  will  be  observed  that  syrups  VII,  VIII  and  XI  were  the 
only  ones  that  furnished  perfectly  bright  preparations  and  did 
not  deposit  or  thicken.  As  the  process  pursued  in  their  prepa- 
ration is  essentially  the  same,  but  differs  considerably  from  the 
others,  it  is  necessary  to  give  it  a  more  critical  examination. 
Of  the  principles  enumerated  as  constituents  of  seneka  rofl^ 
we  find  that  polygalic  acid,  tannic  acid,  pectic  acid,  gum  and 
albumen  are  soluble  in  water  when  isolated,  while  virginic  acid, 
the  coloring  matter,  cerin  and  fixed  oil  are  insoluble.  As  they 
exist  in  the  drug,  however,  both  the  coloring  matter  and  vir- 
ginic acid  are  to  a  certain  extent,  if  not  entirely,  soluble  in  water, 
as  evidenced  by  the  odor  and  color  of  the  infusion.  In  concen- 
trating the  infusion  to  the  consistence  of  syrupy  extract,  the 
greater  portion  of  the  virginic  acid  is  lost,  but  the  coloring 
matter  is  retained.  The  treatment  of  the  syrupy  extract  by 
cold  alcohol,  has  for  its  object  the  separation  of  gum,  albumen, 
and  pectic  acid,  and  undoubtedly  accomplishes  this  object  ; 
polygalic  acid,  traces  of  virginic  acid,  the  coloring  matter  and 
tannic  acid  remains  in  solution  with  the  alcohol,  and  by  subse- 
quent treatment  enter  the  composition  of  the  syrup.  Polygalic 
