154 
The  Ptomaines. 
(  Am.  Jour.  Phanik 
I     April,  1882. 
water,  whereby  a  little  coloring  matter  remained  undissolved,  tlie 
solution  made  alkaline  with  a  little  baryta,  and  the  extraction  with 
ether  repeated.  By  the  treatment  of  the  alkaloid,  which  was  thus 
obtained  nearly  colorless,  with  Avater  containing  acetic  acid,  evaporating^ 
to  dryness,  and  again  dissolving,  a  colorless  solution  was  finally^ 
obtained  which  showed  the  following  behavior  toward  alkaloidal 
reagents : 
Tannic  acid,  a  white,  permanent  precipitate. 
Iodine  in  hydriodic  acid,  a  kermes-brown  precipitate,  gradually  dis-^ 
appearing,  and  furnishing  microscopical  colorless  and  branched,  but 
no  yellow  or  brown  crystals. 
Pkdinic  chloride,  no  precipitate,  but  in  the  course  of  time  yellow 
crystals  appeared,  which  were  different  from  those  of  platinic  chloride. 
Auric  chloride,  a  yellow  precipitate  was  directly  produced,  and  in  a 
short  time  reduction  to  metallic  gold. 
Mercuric  chlmide,  a  white  precipitate. 
Potassium  bichromate,  no  precipitate. 
Picric  acid,  produced  directly  a  yellow  precipitate,  which  in  time 
changed  to  long,  crystalline  tables  of  a  yellow  color. 
The  evaporated  residue  of  the  solution  in  question  dissolved  in  cold 
concentrated  sulphuric  acid  without  coloration,  although  on  warming 
a  slight  red  color  was  produced,  which  did  not  change  to  brown. 
Sulphuric  acid  and  ])otassium  bichromate  gave  no  color  reaction. 
With  Frohde's  reagent  the  solution  remained  likewise  uncolored;  a 
light  yellow  color  which  appeared  after  standing  for  an  hour  disap- 
peared quickly,  as  also  the  insignificant  brown  coloration  on  warming. 
With  iodic  acid  no  iodine  was  liberated,  even  after  the  addition  of 
several  drops  of  sulj)huric  acid;  but,  on  warming,  free  iodine  appeared 
quickly,  and  on  saturating  with  sodi'um  bicarbonate  the  violet  colora- 
tion disappeared.  Sulphuric  acid  containing  nitric  acid  produced  a. 
permanent,  beautiful  lemon-yellow  coloration.  Nitric  acid  produced,, 
likewise,  such  a  coloration,  which,  on  saturating  with  caustic  potassa,, 
changed  to  orange;  on  warming  the  yellow  color  remained,  and  by^ 
the  evaporation  of  the  solution  over  a  moderate  alcohol  flame  a  mate- 
rial of  the  same  color  was  obtained,  which,  on  the  ap;»i'()a(;h  of  a  glass 
rod  moistened  with  ammonia,  passed  into  an  intense  orange  color. 
In  order  to  ascertain  whether  arsenic  was  contained  in  the  ptomaine, 
the  strongly  poisonous  property  of  which  Prof.  Vella  had  demon- 
strated by  an  experiment  on  a  frog,  Selrai  sought  to  destroy  the  same 
