^Vanris'zt™'}  Constituents  and  Properties  of  Potentilla,  109 
gas.  Thus  obtained,  it  exhibits  a  light  straw  color,  and  possesses  a  pun- 
gent terebinthinate  odor.  Its  taste  is  hot  and  camphorous,  followed  by 
a  feeling  of  acrimony,  which  remains  in  the  mouth  for  a  length  of 
time.  It  is  specifically  lighter  than  oreodaphnol,  its  specific  gravity 
being  '934,  and  has  a  boiling-point  of  204°  C.  It  burns  with  a  white 
flame,  giving  off  very  pungent  vapors.  It  is  soluble  in  about  4  parts 
of  95  per  cent,  alcohol.  Iodine  dissolves  in  it,  producing  a  reddish- 
brown  solution.  Nitric  acid  changes  its  color  to  a  deep  red,  with  the 
elevation  of  temperature  and  disengagement  of  nitrous  acid  fumes. 
Nitrous  acid  gave  a  violent  and  rapid  reaction,  and  sulphuric  acid  a 
reddish-brown  solution.  Treated  with  sodium,  no  reaction  was  observed. 
It  is  therefore  the  hydrocarbon  of  oreodaphnol,  generated  by  the 
abstraction  of  water. 
The  hydrocarbon  and  the  oreodaphnol  are  contained  in  the  crude  oil 
in  about  the  proportion  of  one  part  of  the  former  to  two  parts  of  the 
latter.  It  is  upon  the  oreodaphnol  that  the  peculiar  pungency  of  the 
crude  oil  depends. 
ON  THE  CONSTITUENTS  AND  PROPERTIES  OF  THE  GENUS 
POTENriLLA. 
BY  JOHN   M.  MAISCH. 
[Read  at  the  Pharmaceutical  Meeting,  February  i6th.) 
The  genus  Potentilla  belongs  to  the  natural  order  of  Rosaceae,  tribe 
Dryadeae,  and  comprises  mostly  herbs,  together  with  some  shrubby 
plants,  which  are  indigenous  mainly  to  the  temperate  zones  of  the  old 
and  new  continents.  The  generic  name  appears  to  have  been  formed 
from  potens^  powerful,  in  allusion  to  the  reputed  medicinal  properties  of 
some  of  the  species.  At  the  present  time  there  are  but  few  drugs 
officinal  in  any  of  the  pharmacopoeias  which  are  obtained  from  plants 
belonging  to  the  Dryadeae,  the  most  important  being  kousso,  the  inflor- 
escence of  Brayera  anthelmintica^  Kunth,  and  tormentilla^  the  rhizome  of 
Potentilla  tormentilla^  Sibthorp  ;  s.  P.  erecta^  Nestler  ;  s.  Tormentilla 
erecta^  Lin.  ;  s.  T.  officinalis^  Smith.  The  former,  which,  by  End- 
licher,  is  placed  in  the  suborder  Spiraeeae,  but  amongst  the  Dryadeae,  by 
DeCandolle,  contains  in  its  dry  condition,  besides  very  little  volatile  oil, 
a  considerable  proportion  of  tannin,  some  koussin,  resins,  &c.,  to  which 
it  owes  its  taste,  which  at  first  is  somewhat  astringent,  but  afterwards 
bitter,  and  to  a  certain  degree  acrid.  The  latter,  tormentil^  has,  when 
fresh,  a  rather  roselike  odor,  which  is  lost  by  drying,  after  which  it  re- 
tains an  astringent  taste,  due  to  the  presence  of  a  considerable  quantity 
