348 
ON  COLCHICIN. 
amine  and  apparently  isomorphous  with  it.  These  were  con- 
verted into  chloroplatinate  and  analyzed  with  the  following  re- 
sult. 
•7265  grms.  chloroplatinate  gave  of  Pt,    .  -3025 
This  corresponds  to,  per  cent,  .       .  41*65 
Chloroplatinate  of  methylamine  contains,        .  41-62 
The  substance  was  therefore  picrate  of  methylamine. 
The  residue  appeared  to  be  a  mixture.  Analyses  of  different 
portions,  from  different  crystallizations  gave  respectively  39-85, 
40*14,  and  40-23  per  cent,  of  platinum  in  the  chloroplatinate,  nor 
could  any  satisfactory  means  of  separation  be  found. — Amer. 
Jour.  ScL  and  Arts,  May,  1862. 
ON  COLCHICIN. 
By  Prof.  G.  F.  Walz. 
From  a  lengthy  paper,  the  continuation  of  which  is  promised, 
we  make  the  following  extracts: 
The  author  in  the  presence  of  Mr.  Hesse  one  of  the  disco- 
verers of  colchicin,  obtained  this  bitter  principle  in  small,  white, 
oblique,  rhombic  crystals,  possessing  neither  acid  nor  alkaline 
reaction,  soluble  in  water  and  alcohol,  less  in  ether,  permanent 
in  the  air,  and  of  a  bitter  taste.  The  crystallization  is  diffi- 
cult :  the  mother  liquor  separates  at  first  floccules,  which  in 
four  to  six  days  change  into  shining  crystals,  sinking  to  the 
bottom  after  two  or  three  days.  Now  they  must  be  separated, 
or  else  they  will  disappear  again  in  a  few  days. 
Colchicin  contains  nitrogen.  Dissolved  in  water,  it  turns 
yellow,  but  remains  clear  with  dilute  sulphuric  acid  ;  on  boiling, 
floccules  were  separated,  and  the  filtrate  contained  sugar,  but 
no  bitter  principle.  On  neutralizing  with  carbonate  of  potassa, 
darker  color  was  produced,  and  a  considerable  white  flocculent 
precipitate.  The  filtrate  therefrom  was  evaporated  to  dryness, 
and  treated  with  alcohol  and  diluted  alcohol ;  both  solutions 
left  on  evaporation  shining  yellowish  brown  residues  sep- 
arating with  water  white  floccules.  The  precipitate  by  potassa 
dissolves  in  alcohol  with  brownish  yellow  color,  and  the  solu- 
