Am.  Jour.  Pharm.  \ 
July,  1903.  / 
Epinephrin  and  its  Compounds. 
321 
I  have  lately  repeated  a  part  of  my  work  bearing  on  this  question, 
and  without  entering  into  details  I  would  say  that  I  now  find  that  a 
purified  extract  of  the  gland  which  contains  only  such  principles  as 
are  soluble  in  strong  alcohol  and  insoluble  in  ether  behaves  in  the 
following  manner  toward  Fehling's  solution :  if  an  aqueous  solution 
of  such  an  extract  be  poured  into  a  goodly  excess  of  Fehling's  solu- 
tion (Fehling  1  to  water  J^)  and  the  mixture  is  kept  at  the  boiling 
point  for  two  minutes  and  then  at  once  cooled  down,  no  cuprous 
oxide  settles  out.  A  flocculent,  greenish-white  copper  compound 
will,  however,  be  found  suspended  in  the  fluid.  After  boiling  from 
five  to  six  minutes  a  considerable  reduction  occurs  and  yellow 
cuprous  hydrate  begins  to  be  deposited  in  large  amount.  After  boil- 
ing for  fifteen  minutes  the  reduction  appears  to  reach  a  maximum, 
and  a  heavy  deposit  of  cuprous  hydrate,  mixed  with  perhaps  a  trace 
of  the  red  cuprous  oxide,  is  obtained. 
The  extracts  used  in  these  experiments  contained  a  large  percent- 
age of  the  active  principle,  the  amount  being  in  each  case  deter- 
mined by  precipitating  the  principle  from  a  weighed  amount  of 
extract  with  ammonia  or  sodium  carbonate,  drying  and  weighing. 
After  removing  the  crystalline  active  principle  from  a  given  por- 
tion of  extract  with  sodium  carbonate,  the  filtrate,  contrary  to  the 
statements  of  Aldrich,  was  always  found  to  reduce  Fehling's  solution 
even  in  small  amounts,  provided  only  that  the  boiling  was  continued 
for  from  five  to  fifteen  minutes  as  in  the  experiments  with  the  origi- 
nal extracts.  Such  a  filtrate  is  estimated,  both  by  colorimetric  and 
blood-pressure  tests,  to  contain  from  1 5  to  20  per  cent,  of  the  active 
principle,  and  the  amount  of  reduction  is  apparently  proportional  to 
this  unprecipitated  part. 
The  ease  and  rapidity  with  which  the  active  principle  itself 
reduces  Fehling's  solution,  with  deposition  of  cuprous  oxide,  the 
reaction  beginning  far  below  the  boiling  point,  is  in  great  contrast 
to  the  behavior  of  the  above  extracts.  These  extracts  also  have 
no  difficulty  in  reducing  ammoniacal  silver  nitrate  solutions.  A 
fuller  knowledge  of  the  chemical  composition  of  the  gland,  and 
especially  of  the  exact  form  in  which  the  blood-pressure-raising 
principle  exists  in  the  gland,  will  explain  why  an  extract  of  the 
gland  requires  such  prolonged  boiling  before  the  cuprous  hydrate 
is  deposited  from  the  Fehling's  solution. 
I  have  observed  that  the  blue  color  of  a  Fehling's  solution  is 
