150  Sulpho-Molybdate  of  Ammonia,  etc.  {^r^imT*' 
applied,  gave  a  characteristic  color.  This  change  is  due  to  the  oxida- 
tion of  the  solution,  as  all  salts  of  molybdic  acid  or  its  compounds,  when 
heated  in  contact  with  air,  will  finally  turn  blue.  This,  however,  is 
hastened  by  the  contact  of  some  organic  matter  or  any  deoxidising 
agent. 
This  test  may  be  prepared  by  mixing  eight  grains  of  molybdate  of 
ammonia  with  two  drachms  of  sulphuric  acid  (chemically  pure).  The 
milky  solution  is  then  heated  until  it  becomes  clear,  care  being  taken 
not  to  raise  the  heat  too  high,  or  a  change  will  take  place. 
This  solution  should  be  made  fresh  every  time  it  is  wanted  for  use. 
Small  quantities  should  be  used,  as  diiferent  results  may  be  obtained 
by  increasing  the  quantities. 
The  following  are  the  reactions  with  some  of  the  most  important 
alkaloids  and  other  principles. 
1.  Those  which,  at  first,  produce  no  color,  but  afterwards  change 
to  a  light  blue. 
ALKALOIDS,  ETC. 
FIRST  COLOR. 
SECOND  COLOR. 
FINAL  CHANGE. 
1.  Quinia, 
2.  Quinidia, 
3.  Cinchonia, 
4.  Asparagin, 
5.  Strychnia, 
6.  Atropia, 
7.  Caffeia, 
Colorless, 
li 
<< 
Light  Blue. 
it  a 
u  u 
2.  Those  which,  at  first,  produce  a  characteristic  color,  and  after- 
wards, with  exception  of  meconin,  change  to  a  dark  blue. 
ALKALOIDS,  ETC. 
FIRST  COLOR. 
SECOND  COLOR. 
FINAL  CHANGE. 
8.  Santonin, 
Light  Purple, 
"  Yellow, 
Dark  Blue. 
9.  Menispermia, 
10.  Solonia, 
Yellow, 
11.  Veratria, 
Yellow  Green, 
Dark  Brown. 
12.  Meconin, 
Light  « 
Light  « 
13.  Codeia, 
Green, 
Dark  " 
14.  Narcotina, 
Yellow  Green, 
15.  Phloridzin, 
Dark  Blue, 
Permanent. 
16.  Salicin, 
Purple, 
Blue,  then  Brown  Red, 
Dark  Blue. 
17.  Morphia, 
Dark  Red, 
Purple, 
18.  Digitalin, 
Crimson, 
Purple, 
19.  Brucia, 
Brick  Red, 
20.  Aconitia, 
Light  Yellow  Brown, 
Brown, 
21.  Piperina, 
Brown  Red, 
22.  Berberina, 
Purple, 
23.  Cubebin. 
Crimson, 
<<  u 
