498  Astringencies  of  Red  and  Pale  Rose.    ^  Amjufy,ri92i1.arm" 
about  equally  pronounced.  This  description,  however,  does  not  ap- 
ply to  Pale  Rose,  which  is  strikingly  bitter  rather  than  astringent. 
It  is  desirable,  for  the  sake  of  a  proper  understanding,  to  state 
at  once  that  "the  tannin  of  red  rose"  is  present  in  Pale  Rose  as  well, 
but  in  a  very  much  less  proportion. 
A  fair  impression  of  this  amount  may  be  gathered  from  the  fact 
that  a  kilo  of  Pale  Rose  did  not  yield  sufficient  to  permit  of  the 
"tannin"  being  entirely  separated  from  adhering  matter,  while  the 
same  weight  of  Red  Rose  gave  an  abundant  sample  of  the  purified 
principle. 
In  the  case  of  Pale  Rose,  as  in  Red  Rose,  the  presence  and  close 
association  of  much  larger  amounts  of  the  "quercitrin"  of  other  ob- 
servers makes  the  isolation  of  the  astringent  principle  both  tedious 
and  wasteful. 
For  a  proper  comparison  of  the  following  notes  on  Pale  Rose, 
reference  should  be  had  to  the  article  of  last  year  on  Red  Rose. 
When  Pale  Rose  was  boiled  with  successive  portions  of  water, 
the  reddish  color  of  the  material  and  the  bitterness  were  entirely 
removed,  and  they  failed  to  reappear  upon  subsequent  drying  of  the 
undissolved  portion.  The  infusion  was  feebly  acid  to  litmus.  While 
the  first  impression  made  by  this  infusion  on  taste  was  of  bitterness, 
the  last  was  plainly  of  astringency.  Diluted  sulphuric  acid  devel- 
oped a  reddish  color  and  a  distinct  opalescence  in  the  infusion.  Upon 
boiling,  a  precipitate  of  burr-like  aggregates  was  formed,  identical 
in  appearance  and  properties  with  those  obtained  through  like  treat- 
ment of  Red  Rose. 
Except  for  the  much  smaller  proportion  of  astringency  and  the 
relatively  greater  bitterness,  the  physical  properties  of  the  infusions 
of  the  two  roses  were  found  to  be  very  similar,  while  behavior  to- 
ward reagents  further  demonstrated  a  similarity  of  ingredients.  For 
instance,  from  the  infusion  of  Pale  Rose,  as  from  that  of  Red  Rose, 
hide  powder  removed  all  astringency  and  bitterness ;  all  acidity  to 
litmus,  and  all  color  except  a  straw-yellow.  The  resultant  fluid  was 
changed  to  pink  by  the  addition  of  diluted  sulphuric  acid. 
In  an  attempt  to  isolate  and  purify  the  astringent  substance,  the 
bulk  of  the  infusion  was  concentrated,  cooled  and  shaken  with  acetic 
ether,  which  solvent  removed  the  greater  part  of  the  astringent  prin- 
ciple, as  subsequently  found  through  the  failure  of  diluted  acid  to 
produce  in  this  liquid  the  burr-like  aggregates  upon  heating. 
The  recovery  of  the  acetic  ether  yielded  a  small  amount  of 
