ON  THE  CONSTITUTION  OF  SCAMMONY. 
575 
If  this  neutral  body  be  dissolved  in  solution  of  potash,  the 
potash-salt  of  an  acid  produced  from  it  is  obtained.  This  sep- 
arates, on  the  addition  of  sulphuric  acid,  in  white  flakes,  which 
unite  to  form  oily  drops  when  heated  ;  on  cooling,  these  appear 
as  a  beautifully  satiny  mass.  The  alcoholic  solution  has  a  de- 
cidedly acid  reaction. 
The  crystals  obtained  from  the  alcoholic  solution  are  less 
lustrous,  and  consist  of  needles  grouped  like  wavellite  round  a 
central  point,  which  are  also  formed  by  the  fused  acid  on  cool- 
ing. The  melting  point  was  found  to  be  140 — 142°  F.  The 
acid  produced  by  potash  from  the  first-mentioned  neutral  body, 
and  separated  by  sulphuric  acid,  was  dissolved  in  alcohol  with 
the  addition  of  an  excess  of  ammonia ;  and  this  solution  was 
precipitated  by  nitrate  of  silver.  The  flocculent  precipitate  ob- 
tained gave  on  analysis 
0  49-39 
49-26 
30= 
100 
49-58 
H  7-89 
8-09 
27 
27 
7-43 
0 
6 
48 
13-24 
Ag  29-33 
29-62 
1 
108 
29-75 
e  analysis  of  the  free  acid  gave 
C  70-28 
70-01 
30  = 
:180 
70-31 
H  11-13 
12-00 
28 
28 
10-93 
0  18-59 
17-99 
6 
48 
18-76 
Consequently  the  neutral  body  has  the  composition  C28  H28 
O4,  and  would  be  isomeric  with  the  aldehyde  of  cenanthylic  acid. 
The  acid  produced  therefrom  by  potash  would  have  the  formu- 
lae C30  H28  O6. 
The  author  now  found  that  in  dissolving  the  neutral  body  in 
potash  a  volatile  body  escapes,  which  may  be  distilled  off  from 
the  solution  and  collected  in  a  receiver  ;  this  volatile  body 
proved  to  be  an  alcohol  of  the  formula  C26  H28  O2.  This  alco- 
hol is  best  obtained  directly  by  the  treatment  of  scammony  in 
its  alcoholic  solution  with  potash,  as  follows : — 
2.  Decomposition  of  the  Resin  by  Potash. — If  fragments  of 
hydrate  of  potash  be  added  to  the  colorless,  building,  alcoholic 
solution  of  the  resin,  this  immediately  acquires  a  yellow  color. 
When  the  boiling  is  continued,  the  fluid  becomes  turbid  with 
separation  of  dark  flakes,  which  only  dissolve  with  difficulty  in 
boiling  alcohol,  are  precipitated  again  on  cooling,  and  can  be 
