440       ACRID  PRINCIPLE  OF  RANUNCULUS  SCELERATUS. 
boiling-point,  there  is  only  the  pressure  of  the  atmosphere  to  be 
overcome ;  but  if,  on  the  contrary,  the  lowest  stratum  be  heated 
to  boiling,  the  pressure  of  the  upper  strata  is  to  be  overcome 
besides  that  of  the  atmosphere.  The  fluid  must,  therefore,  in 
this  case,  boil  at  a  higher  temperature ;  but  if  there  be  in  it  a 
coiled  platinum  wire,  passing  from  below  upwards,  the  heat  will 
be  conducted  from  the  bottom  to  the  superior  strata,  and  the 
uppermost  stratum  will  boil  sooner  than  the  lowest.  Now  it  is 
evident  that  as  oil  of  vitriol  is  a  mixture  of  anhydrous  and  hy- 
dra ted  acid,  and  the  former  boils  at  a  lower  temperature  than 
the  latter,  the  anhydrous  acid  will  carry  over  more  of  the  hy- 
drated  acid  with  it  when  the  distillation  is  carried  on  at  a  high 
temperature,  than  when  it  is  effected  at  a  lower  one.  If,  there- 
fore, the  uppermost  stratum  boils,  comparatively  very  little  of 
the  hydrated  acid  can  be  carried  over.  The  author,  however, 
thinks  it  not  improbable  that  the  catalytic  action  of  the  plati- 
num may  have  something  to  do  with  the  effect  produced. — 
Ibid.,  from  VerhandL  der  Wurzburger phys.-med.  Gfesellsch.,  Oct. 
30,  1858. 
ON  THE  ACRID  PRINCIPLE  OF  RANUNCULUS  SCELERATUS. 
By  0.  L.  Erdmann. 
In  compliance  with  the  request  of  Professor  Clarus,  who  is  in- 
vestigating the  physiological  and  therapeutical  action  of  Pulsa- 
tilla and  other  Ranunculaceae,  the  author  made  some  experiments 
with  the  acrid  principle  of  Ranunculus  sceleratus. 
The  fresh  juice  mixed  with  the  aqueous  liquid  from  the  second 
expression  of  the  plant,  with  the  addition  of  water,  yields  an 
acrid  clear  distillate  of  a  disagreeable  odor,  which,  whether 
kept  in  open  vessels,  or  in  well  filled  and  corked  vials,  is  ren- 
dered milky,  and  gradually  precipitates  anemonic  acid,  which 
Schwarz  obtained  from  the  aqueous  distillate  of  Anemone 
Pulsatilla  s.  Pulsatilla  pratensis.  Dr.  Trommsdorff  remarks, 
that  from  a  concentrated  Aqua  pulsatilla,  anemonic  acid,  besides 
anemoninis  separated  in  open  and  in  well  corked  bottles;  anemonic 
acid  is  precipitated  first,  anemonin  afterwards ;  the  not  con- 
centrated water  only  precipitates  anemonic  acid ;  accordingly, 
