BERBERIN  IN  HYDRASTIS  CANADENSIS. 
143 
Concentrated  nitric  acid  produces  a  deep  red  solution  under 
disengagement  of  nitrous  acid  vapors. 
It  does  not  emit,  any  trace  of  ammonia,,  when  boiled  with  a 
diluted  solution  of  caustic  potassa,  but  clots  together  and  is  trans- 
formed into  a  brown  resinous  substance,  which  adheres  strongly 
to  the  sides  of  the  vessel.  This  resinous  body  is  insoluble  in 
water  but  soluble  in  alcohol,  to  which  it  imparts  a  bitter  taste. 
Heated  with  soda-lime  it  emits  ammonia. 
Dry  chlorine  gas  transforms  it  into  a  red  body,  which  is  readily 
soluble  in  water. 
Polysulphide  of  ammonium,  when  mixed  with  a  hot  solution 
of  this  so-called  hydrastin,  produces  immediately  a  red  brown 
precipitate. 
Sulphate  of  copper  is  precipitated  with  a  yellowish  green ; 
nitrate  of  silver,  chloride  of  zinc,  corrosive  sublimate,  chlorate 
of  potassa,  and  chloride  of  platinum  with  a  yellow  color.  A  so- 
lution of  bichromate  of  potassa  when  mixed  with  a  solution  of 
this  body  throws  down  an  orange-yellow,  cyanide  of  potassium 
an  ochre-yellow,  and  ferrocyanide  of  potassium  a  greenish-yellow 
precipitate. 
When  moderately  heated  it  exhibits  a  deeper  yellow  tint ;  the 
original  bright  yellow  color  is,  however,  restored  on  cooling ;  if 
heated  to  a  higher  temperature  it  melts  like  a  resin  and  leaves 
finally  a  light  coaly  residue. 
All  these  reactions  coincide  so  completely  with  the  reactions 
of  muriate  of  berberin,  that  I  should  not  have  hesitated  a  mo- 
ment on  this  evidence  alone  to  declare  its  identity  with  that  al- 
kaloid. 
(The  fact  that  berberin  is  precipitated  from  its  solution  by 
hydrochloric  acid  explains  the  peculiar  method  of  preparation 
of  hydrastin.) 
To  quiet,  however,  all  doubts,  I  undertook  an  elementary 
analysis  of  it,  which  led  to  the  following  results: 
1.  The  nitrogen  was  determined  by  Will  and  Varrentrapp's 
method.  Before  commencing  the  experiment,  I  dried  the  sub- 
stance for  10  hours  at  a  temperature  of  100°  C.  The  quantity  of 
material  employed  amounted  0-416  grammes.  It  yielded  0-236 
ammonia-chloride  of  platinum.  This  corresponds  to  3-563  per 
cent,  of  nitrogen.  Muriate  of  berberin  at  100°  C.  requires 
3-57  per  cent. 
