356  Alkaloids  of  Fiturie.  { ^'"juiTirsr""'' 
after  standing  for  months.  All  these  compounds  are  very  hygroscopic, 
especially  the  sulphate,  and  are  very  readily  soluble  in  alcohol. 
Neither  concentrated  hydrochloric  acid  nor  nitric  acid  changes 
the  color  of  the  alkaloid  in  the  cold,  but  when  warmed,  hydrochlo- 
ric acid  imparts  a  slightly  reddish  color  and  nitric  acid  turns  it 
yellow.  Concentrated  sulphuric  acid  turns  it  brown  after  some  time, 
immediatelv  when  warmed. 
Platlnic  chloride  does  not  precipitate  an  aqueous  solution  of  the 
alkaloid  (1:100  aq.)  so  long  as  the  alkaloid  is  in  excess,  but  when  the 
solution  has  become  neutralized,  the  addition  of  another  drop  of  pla- 
tlnic chloride  throws  down  a  slight  yellowish  Hocculent  precipitate, 
which  dissolves  on  heating  but  does  not  reappear  on  cooling  ;  if  a  larger 
(quantity  of  the  platinic  chloride  be  added,  the  precipitate  still  dis- 
solves on  the  application  of  heat,  but  on  cooling  reappears  in  a  crys- 
talline condition.  In  a  solution  of  1  part  of  the  hydrochloride  of  the 
alkaloid  to  50  of  water,  a  precipitate  similar  to  the  above  is  thro^vn 
down,  and  if  lieated  a  part  redissolves,  the  undissolved  portion  turns 
to  an  orantre-vellow  color  and  becomes  crystalline — the  dissolved  salt 
also  crystallizes  only  on  cooling.  Under  the  microscope  the  crystals 
appear  to  have  the  form  of  the  octahedron,  or  combinations  of  that 
with  other  forms  belonging  to  the  cubical  system.  More  dilute  solu- 
tions of  the  hydrochloride  are  not  precipitated  by  platinic  chloride. 
In  an  aqueous  solution  of  1  part  of  the  alkaloid  to  100  water: 
Mercuric  chloride  throws  down  a  white  cheesy  precipitate  insoluble  in 
excess  of  the  precipitant.  Copper  sulphate  a  light  green  precipitate 
insoluble  in  an  excess  of  the  alkaloid.  A  few  drops  of  gold  chloride 
give  a  reddish-white  precipitate,  which  disappears  on  shaking ;  a  lar- 
ger quantity  gives  a  persistent  flocculent  reddish-white  precipitate. 
Tannic  acid  gives  a  grayish-white  precipitate  easily  soluble  in  hydro- 
chloric acid.  The  double  iodide  'of  mercury  and  potassium  gives  a 
heavy  white  crystalline  precipitate. 
The  alkaloid  behaves  very  like  nicotina  with  })icric,  phosphomolyb- 
dic  and  metatungstic  acids ;  the  addition  of  picric  acid  thro^vs  down  a 
yellow  precipitate  soluble  in  hydrochloric  acid.  Phosphomolybdic 
acid  forms  a  yellowish-white  amorphous  precipitate,  insoluble  in  cold 
dilute  hydrochloric  acid,  easily  and  completely  dissolved  on  warming. 
The  precipitate  with  nicotina  is  a  dirty  yellowish-white,  amorphous, 
insoluble  in  cold  dilute  hydrochloric  acid,  soluble  when  warmed,  but 
apparently  not  so  readily  as  is  the  precipitate  from  the  piturie  alkaloid. 
