Am'siXSarm"}     Tyrotoxicon  in  Ice  Cream,  Milk,  etc,  453 
was  made.  These  tests  were  followed  by  negative  results,  until  about 
three  months  after  the  experiment  was  begun.  I  then  succeeded  in 
getting  the  poison  from  one  of  the  bottles.  The  method  of  testing 
for  it  was  as  follows:  The  coagulated  milk  was  filtered  through 
heavy  Swedish  filter  paper.  The  filtrate  was  colorless  and  decidedly 
acid  in  reaction.  It  was  rendered  feebly  alkaline  by  the  addition  of 
potassium  hydrate,  then  agitated  with  ether.  After  separation  the 
ethereal  layer  was' removed  with  a  pipette,  allowed  to  run  through  a 
dry  filter  paper  to  remove  a  flocculent,  white  substance  which  floated 
in  it,  and  then  allowed  to  evaporate  spontaneously.  If  necessary  this 
residue  was  dissolved  in  water  and  again  extracted  with  ether.  On 
the  evaporation  of  the  ether  the  tyrotoxicon  was  recognized  by  its 
crystalline  appearance,  by  its  odor,  and  by  placing  a  small  bit  on  the 
tongue.  As  the  ether  takes  up  some  water,  there  is  usually  enough 
of  the  latter  left  after  the  spontaneous  evaporation  of  the  ether  to 
hold  the  poison  in  solution,  and  in  order  to  obtain  the  crystals  this 
aqueous  solution  must  be  allowed  to  stand  for  some  hours  in  vacuo 
over  sulphuric  acid. 
From  one  half  gallon  of  the  milk  there  was  obtained  quite  a  con- 
centrated aqueous  solution  of  the  poison  after  the  spontaneous  evapor- 
ation of  the  ether.  Ten  drops  of  this  solution  placed  in  the  mouth 
of  a  small  dog  three  weeks  old  caused,  within  a  few  minutes,  frothing 
at  the  mouth,  retching,  the  vomiting  of  frothy  fluid,  muscular  spasm 
over  the  abdomen,  and  after  some  hours  watery  stools.  The  next  day 
the  dog  seemed  to  have  partially  recovered,  but  was  unable  to  retain 
any  food.  This  condition  continuing  for  two  or  three  days,  the 
animal  was  killed  with  chloroform.  No  examination  of  the  stomach 
was  made. 
It  may  be  remarked  here  that  I  have  elsewhere  pointed  out  the 
necessity  of  using  pure  ether  for  these  extractions,  as  some  samples 
of  ether  contain  an  irritating,  ptomaine-like  substance. 
June  13,  1886,  I  received  from  Dr.  Henry  B.  Baker,  Secretary  of 
the  Michigan  State  Board  of  Health,  a  pint  bottle  about  two-thirds 
full  of  melted  ice  cream,  with  the  request  that  I  analyze  it,  as  some 
18  persons  had  been  seriously  affected  by  eating  of  it.  Dr.  Baker 
also  sent  some  of  the  vanilla  which  had  been  used  as  flavoring.  It 
was  thought  that  the  poison  would  be  found  in  the  vanilla,  because 
some  lemon  ice  cream  furnished  at  the  same  gathering  had  not  affec- 
ted those  who  ate  it     As  the  readiest  means  of  deciding  this,  my  an- 
