504  Proteids  of  Seeds  of  Abrus  Precatorius.  {Am'octuyi8P87arm' 
product  extracted  by  these  observers  the  name  "  abrin  "  was  given ; 
and  though  it  was  decided  that  abrin  was  closely  allied  to  "  plant- 
albumin,"  yet  no  experiments  were  recorded  to  show  whether  the 
product  was  a  mixture  or  a  single  proteid.  They  obtained  it  by 
making  a  watery  extract  of  the  crushed  seeds  and  precipitating  with 
alcohol,  the  precipitate  being  afterwards  collected  and  dried. 
Before  proceeding  to  an  examination  of  the  physiological  action  of 
the  jequirity,  it  seemed  to  me  desirable  to  determine  the  kind  of  pro- 
teids present  in  the  seeds,  and  the  present  communication  embodies 
the  results  of  the  inquiries  made  with  a  view  to  such  determination. 
Method  of  extraction  of  the  proteids. — The  method  used  was  based 
on  the  supposition  that  the  proteids  present  in  abrus  were  similar  to 
those  in  other  seeds,  consisting  chiefly  of  proteids  of  the  globulin  and 
albumose  classes. 
The  finely  ground  seeds  were  shaken  first  of  all  with  chloroform 
to  remove  the  red  cuticle  which  sinks  in  this  liquid,  so  that  the  yellow 
kernel-powder  could  be  readily  removed,  and  obtained  in  the  dry  state 
by  allowing  the  chloroform  to  evaporate. 
The  powder  obtained  was  then  extracted  with  15  per  cent,  sodium 
chloride  solution  for  twenty-four  hours,  and  the  mixture  filtered.  The 
yellowish  filtrate  was  distinctly  acid  and  gave  a  copious  precipitate 
onboiling.  The  proteids  were  separated  from  this  filtrate  in  two 
ways : — 
1.  Saturation  with  neutral  ammonium  sulphate  and  shaking  for 
four  hours  throws  down  all  the  proteids  in  solution ;  the  filtrate,  after 
saturation,  giving  none  of  the  proteid  tests. 
2.  Saturation  with  sodium  chloride  and  shaking  for  many  hours 
gives  only  a  scanty  precipitate,  which  becomes  copious  on  adding  a 
large  excess  of  glacial  acetic  acid.  All  the  proteids  are  only  with 
difficulty  precipitated  by  this  mode  of  saturation,  even  after  prolonged 
shaking. 
Since  ammonium  sulphate  so  readily  throws  down  all  the  proteids 
in  solution,  the  precipitate  caused  by  it  was  used  in  the  following 
manner  in  the  examination  of  the  proteids  :  The  precipitate  was  col- 
lected and  dissolved  by  adding  distilled  water,  and  the  solution 
dialyzed  in  running  water  (with  thymol)  for  five  to  seven  days. 
Dialysis  caused  a  copious  precipitate,  which  was  collected  and  washed 
with  distilled  water  (previously  boiled  to  remove  carbon  dioxide)  until 
no  proteid  in  solution  was  present  in  the  washings.    The  precipitate 
