Am.  Jour  Pharm.  |        Bark  of  RoUnia  Pseudacacia.  341 
August,  1913.     j  *  0  1 
place  it  in  the  group  of  "  phasins,"  or  non-poisonous  agglutinants. 
Some  still  more  surprising  statements  are  made  by  Professor 
Robert  (loc.  ext.,  p.  83),  which  may  literally  be  translated  as  fol- 
lows: "  For  distinguishing  the  robin  of  Robinia  bark  from  ricin 
the  property  of  hydrolyzing  sinigrin,  as  found  by  Power,  would  be 
admirably  adapted,  as  this  is  not  otherwise  possessed  by  a  single 
vegetable  agglutinin.  Experiments  have  shown,  however,  that 
Power's  statements  are  not  valid  for  the  robin  of  Robinia  bark 
prepared  by  me  (Robert)  and  preserved  in  a  dry  state.  It  does 
not  hydrolyze  sinigrin  even  by  its  action  for  two  days  in  an  incu- 
bator and  does  not  otherwise  possess  the  property  of  hydrolyzing 
glucosides.    It  also  has  no  coagulating  effect  on  milk." 
It  is  exceedingly  unfortunate  that  Professor  Robert  should  have 
given  such  prominence  to  the  results  of  experiments  from  which 
thoroughly  incorrect  inferences  are  liable  to  be  drawn,  especially 
by  those  who  cannot  conveniently  repeat  them,  and  he  does  not 
seem  to  have  considered  it  necessary  to  ascertain  the  cause  of  his 
failure  to  obtain  the  results  recorded  by  me.  As  the  subject  is  one 
of  considerable  importance,  I  have  deemed  it  desirable  to  present 
such  facts  as  are  believed  to  be  sufficient  to  prove  the  incorrectness 
of  Professor  Robert's  conclusions,  and  to  substantiate  in  every  re- 
spect the  accuracy  of  the  statements  previously  recorded  by  me 
regarding  the  toxic  action  and  other  properties  of  the  protein  of 
Robinia  bark. 
In  the  first  place  it  was  noted  in  my  paper  on  this  subject  in 
1890  that  a  decoction  made  by  boiling  100  grammes  of  the  bark 
with  water  was  taken  without  any  ill  effect  or  any  perceptible 
action,  whereas  a  cold  infusion  of  about  5  grammes  of  the  bark 
was  in  one  instance  so  violent  in  its  action  as  nearly  to  prove  fatal. 
It  was  thus  evident  that  the  activity  of  the  poisonous  substance  was 
destroyed  at  the  temperature  of  boiling  water,  and  this  observation 
suggested  not  only  the  protein  nature  of  the  substance  but  also  the 
method  subsequently  employed  for  its  isolation.  Moreover,  the 
protein  material,  as  precipitated  by  alcohol  from  the  liquid  obtained 
by  macerating  the  ground  bark  with  cold  water,  when  collected, 
washed  with  alcohol,  and  dried  in  a  vacuum  or  over  sulphuric  acid, 
possessed  the  same  poisonous  properties  as  the  bark.  When  ad- 
ministered to  a  large  dog  in  an  amount  representing  about  30 
grammes  of  the  bark,  it  caused  severe  vomiting,  which  continued 
at  intervals  for  several  hours,  and  a  considerably  smaller  quantity 
