"^"^Sept ^^1^81^°^" }  Pt'^pci'^'Cition  and  Composition  of  Colchicin.  447 
afforded  upon  analysis  numbers  which  correspond  to  the  empirical 
formula  C,^ll,,^0,+2Hfi. 
According  to  Hiibler^  colchicein  has  the  same  composition  as  col- 
chicin ;  it  is  possible,  however,  that  the  colchicein  analyzed  by  Hiibler 
was  not  perfectly  pure,  and  still  contained  some  adhering  beta-colchico- 
resin,  whereby  too  large  an  amount  of  carbon  was  found. 
An  alcoholic  solution  of  colchicein  feebly  reddens  litmus  paper,  and 
thus  bears  the  character  of  an  acid.  Hiibler  had  indeed  formed  there- 
with compounds  with  barium  and  calcium,  the  correctness  of  which  is 
confirmed  by  the  experiments  of  the  author.  The  compounds  of  col- 
chicein with  bases,  with  the  exception  of  the  potassium  and  sodium 
compounds,  are  insoluble  in  water,  but  readily  soluble  in  alcohol  and 
diloroform ;  they  are  amorphous,  and  of  a  yellowish-white  color,  the 
copper  compound  of  a  beautiful  green  color.  The  author  does  not 
doubt  but  that  it  will  be  possible  to  form  also  compounds  of  colchicein 
with  the  other  metallic  oxides. 
Beta-colchicoresin,  the  resinous  product  of  decomposition  previously 
referred  to,  forms  a  blackish-brown  amorphous  mass.  It  is  absolutely 
insoluble  in  water  and  in  ether,  very  sparingly  soluble  in  aqueous 
alcohol,  but  readily  in  95  per  cent,  alcohol,  the  latter  solution  acquir- 
ing a  milk-like  turbidity  upon  the  addition  of  water.  It  is  readily 
soluble  in  chloroform,  carbon  bisulphide,  solution  of  potassa  and 
-ammonia  water,  forming  dark  brown  solutions.  With  the  ordinary 
precipitating  agents  it  only  affords  a  precipitate  with  phosphomolyb- 
dic  acid,  which  is  explained  by  the  fact  that  it  can  only  be  tested  with 
reagents  in  its  strong  alcoholic  solution.  The  color  reaction  with 
potassium  nitrate  and  sul])huric  acid  is  produced  with  the  same  char- 
acteristic sensitiveness  as  with  colchicin ;  with  ferric  chloride  it  yields 
a  brownish-green  coloration.  It  becomes  soft  like  wax  between  the 
fingers,  and  melts  at  90 °C.  Beta-colchicoresin  is  best  obtained  by 
heating  colchicoresin  with  hydrochloric  acid.  For  the  purpose  of 
analysis  a  product  was  employed  which  had  been  previous  carefully 
boiled  with  water,  then  dissolved  in  alcohol,  the  solution  filtered, 
allowed  to  evaporate  upon  watch-glasses,  and  finally  dried  at  85°C. 
Figures  were  thus  obtained  from  which  was  calculated  the  empirical 
formula  C34II39NO10. 
Residue  from  the  3Iotlier-liquid. — The  residue  left  by  the  evapora- 
tion of  the  mother-liquid  as  obtained  in  the  preparation  of  the  colchi- 
-cein,  after  the  complete  removal  of  the  latter  by  means  of  chloroform, 
