200 
AN  ESSAY  ON  GILLENIA  TRIFOLIATA. 
blocks  of  chroraate  and  all,  was  driven  to  a  remote  part  of  the 
glass  ;  perhaps  beyond  the  reach  of  further  electrical  action. 
These  experiments  look  very  much  like  proving  that  chemical 
attraction  is  sometimes  exerted  at  sensible  distances,  and  very 
sensible  distances.  But,  one  of  the  fluids  being  volatile,  its  parti- 
cles may  be  brought  within  the  attractive  action  of  the  sulphuric 
acid  by  the  well  known  affinity  of  that  acid  for  atmospheric 
vapor  causing  currents  ;  and  in  the  case  of  alcohol  the  direct 
affinity  of  the  acid  for  that  substance  accounts  for  its  greater  ac- 
tivity. This  view  is  corroborated,  as  glycerine,  a  non-volatile 
oxygenous  compound,  produced  no  action  on  the  acid  mixture ; 
but  when  a  small  drop  of  alcohol  was  stirred  up  intimately  with 
the  glycerine,  the  change  in  the  acid  mixture  soon  detected  its 
presence.  (Does  not  this  suggest  that  the  acid  mixture  of  chro- 
mate  of  potassa  and  sulphuric  acid  may  serve,  in  many  cases,  to 
bring  to  light  alcoholic  adulterations  of  liquids,  as  well  as  some- 
times a  mixture  of  different  oils  ?) 
On  trial  with  chromic  acid  in  water,  I  was  not  successful  in  ob- 
taing  like  results  with  the  oils  ;  that  is,  they  effected  no  change  in 
the  acid.  Does  the  sulphuric  acid  in  the  mixture,  in  consequence 
of  its  affinity  for  water,  deprive  the  chromic  acid  of  a  part  of  its 
oxygen  and  the  oils  of  an  equivalent  of  hydrogen,  so  as  to  form 
that  fluid  ?  Be  this  as  it  may,  the  sulphuric  acid  plays  an  im- 
portant part  in  the  phenomena  described. 
Richmond,  Indiana,  3d  mo.  2>d}  1856. 
AN  ESSAY  ON  GILLENIA  TRIFOLIATA. 
By  William  B.  Stanhope. 
(A)i  Inaugural  Essay  presented  to  the  Philadelphia  College  of  Pharmacy •) 
Professor  R.  P.  Thomas,  when  lecturing  on  Gillenia  trifoliata, 
before  the  Class  of  the  Philadelphia  College  of  Pharmacy,  ex- 
pressed a  desire  that  some  one  of  the  students,  wanting  a  subject 
for  a  Thesis,  would  take  up  this  article  for  that  purpose  and  ex- 
amine it.  In  compliance  with  this  request,  I  have  been  induced 
to  make  some  experiments,  for  the  purpose  of  isolating,  if  possi- 
ble, the  active  principle. 
Experiment  1st.  Eight  ounces  of  the  coarsely  powdered 
cortical  portion  of  the  root  was  exhausted  by  percolation  with 
