Am.  Jour.  Pharm. 
July,  1903. 
Epinephrin  and  its  Compounds. 
303 
roughly  isolated  the  blood-pressure-raising  constituent  in  the  form 
of  a  definite  chemical  compound. 
In  1895  B.  Moore,1  working  in  Schafer's  laboratory,  came  to  the 
conclusion  that  Vulpian's  chromogen  and  the  blood-pressure-raising 
constituent  are  identical.  He  based  this  opinion  on  the  fact  that 
chemical  operations  which  destroy  the  color  reactions  of  the  chro- 
mogen also  deprive  ■  the  blood-pressure-raising  constituent  of  its 
power  to  raise  the  arterial  pressure.  That  the  solubilities  of  the 
active  principle  are  the  same  as  those  of  the  chromogen  appeared 
also  to  support  this  opinion. 
Fraenkel,2  working  with  residues  obtained  with  the  help  of  alco- 
hol and  acetone  as  solvents,  also  concluded  that  the  blood-pressure- 
raising  constituent  and  Vulpian's  chromogen  are  one  and  the  same 
substance.  His  residues  did  not  contain  pyrocatechin,  and  he  con- 
cluded from  their  behavior  toward  ferric  chloride  and  other  oxidiz- 
ing agents  that  the  essential  principle  of  these  residues  is  a 
nitrogenous  derivative  of  the  ^r^dihydroxy-benzene  series. 
In  1 897  Abel  and  Crawford3  showed  that  the  active  principle  may- 
be precipitated  from  aqueous  extracts  of  the  gland  by  treatment 
with  benzoyl  chloride  and  sodium  hydrate.  Fraenkel4  had,  the  year 
before,  shown  that  a  syrupy  substance  is  thrown  out  when  benzoyl 
chloride  is  shaken  up  with  a  pytidin  solution  of  an  extract  of  the 
gland,  but  he  did  not  attempt  to  decompose  it  in  order  to  ascertain 
whether  it  was  in  reality  a  benzoyl  derivative  of  the  blood-pressure- 
raising  constituent.  Abel  and  Crawford,  however,  were  unaware  of 
the  fact  that  Fraenkel  had  made  trial  of  benzoyl  chloride  in  a  pyridin 
solution,  until  their  own  work  was  nearly  completed.  These  writers 
decomposed  their  benzoyl  product  with  hot  dilute  sulphuric  acid 
and  obtained  the  active  principle  in  the  form  of  a  sulphate  of  a  tarry 
consistency,  which  possessed  great  physiological  activity,  gave  the 
color  reactions  of  Vulpian,  reduced  silver  nitrate,  and  possessed  the 
other  specific  qualities  of  suprarenal  extracts.  They  did  not  suc- 
ceed in  splitting  off  pyrocatechin  from  their  active  principle  by  boil- 
ing with  dilute  hydrochloric  acid.    They  also  stated  that  their  si.il- 
xJour.  Physiol.,  XVII,  1895  ;  Proc.  Physiol.  Soc,  London,  p.  xiv  ;  ibid.,  Vol. 
XXI,  1897. 
2  Wiener  med.  Blatter,  1896,  Nos.  14-16. 
3  The  Johns  Hopkins  Hospital  Bulletin,  July,  1897,  No.  76. 
4  Loc.  tit. 
