ON  SCAMMONY. 
257 
it  became  brittle.  It  may  be  easily  pounded  into  a  perfectly 
white  powder.     The  analysis  gave — 
C  56-69  56-67  76=456  56-78 
H  8-34  8-42  67  67  8-34 
0  ••  35    280  34-88 
Scammonic  Acid,  C76H64043+4HO.— If  the  resin  be  put  into 
a  boiling  solution  of  baryta,  it  is  dissolved  with  evolution  of  an 
aromatic  odor,  resembling  that  of  oil  of  hops,  and  forms  a  clear 
fluid.  From  this  solution  muriatic  acid  does  not  precipitate  the 
resin.  The  baryta  is  thrown  down  by  sulphuric  acid  in  slight 
excess,  and  carbonate  of  lead  is  then  added  to  get  rid  of  the 
excess  of  sulphuric  acid ;  lastly,  a  small  quantity  of  lead  is 
thrown  down  by  sulphuretted  hydrogen.  In  this  way  a  strongly 
acid  fluid  is  obtained,  which,  when  evaporated,  leaves  an  amor- 
phous, cracked,  gum-like  mass,  exhibiting  no  traces  of  crystalli- 
zation. This  mass  is  allowed  to  stand  for  a  long  time,  by  which 
means  stellate  groups  of  a  fatty  body,  insoluble  in  water,  sepa- 
rate ;  these  are  easily  removed  by  dissolving  the  residue  in 
water. 
The  author  has  analysed  the  lead-salt  of  this  acid.  It  was 
obtained  by  slightly  supersaturating  the  solution  of  the  acid 
with  ammonia,  and  then  adding  solution  of  acetate  of  lead.  The 
analysis  gave — 
c 
34-55 
76= 
=456 
34-77 
H 
5-23 
64 
64 
4-88 
0 
26-86 
43 
344 
26-29 
PbO 
33-36 
4 
446-4 
34-06 
If  the  solution  of  this  acid,  or  that  of  the  resin  in  solution  of 
potash  be  boiled  with  an  excess  of  sulphuric  acid,  oil  drops 
gradually  separate  on  the  surface ;  these  solidify  in  a  crystalline 
form.  They  are  purified  by  repeated  washing.  This  substance 
is  the  author's : 
Scammonolic  Acid,  C36H3607  An  acid  fusible  at  131—133°, 
insoluble  in  water,  soluble  in  alcohol  and  ether.    Its  solutions 
have  a  strong  acid  reaction.    From  alcohol  the  acid  crystallizes 
in  microscopic  needles.    The  analysis  gave — 
C      70-01      69-74      70-28      36=216  70-13 
H      11-95      12-03      12-06      36      36  11-68 
O        .  .  .  .  .  .  7      56  18-19 
17 
