18  The  Color  of  Fluorescent  Solutions. 
harden  ;  minute  glistening  particles  of  the  drug  have,  however,  made 
their  appearance  on  the  surface  of  these  pills,  and  also  on  the  bottle, 
indicating  that  they  should  not  be  made  too  long  before  they  are  re- 
quired to  be  used. 
In  the  conversion  of  .Dover's  powder  into  pills,  soluble  cream  of 
tartar  only  was  used ;  for  those  of  nitrate  of  potash  and  chlorate  of 
potash  one  grain  to  the  drachm  of  gum  tragacanth  was  employed,  in 
addition  to  the  soluble  cream  of  tartar ;  for  those  of  citrate  of  potash 
and  gallic  acid  took  twTo  grains  of  the  gum  to  each  dozen.  The  ni- 
trate of  potash,  chlorate  of  potash,  gallic  acid  and  citrate  of  potash 
pills  were  dried  at  a  gentle  heat ;  the  three  former  keep  well  in  boxes  • 
those  of  citrate  of  potash  should  be  kept  in  bottles  in  contact  with 
lycopodium.  With  the  exception  of  the  gallic  acid,  all  these  pills  are 
smaller  than  an  ordinary  five-grain  pill. 
I  have  also  prepared  four-grain  pills  of  chloride  of  ammonium, 
using  the  soluble  cream  of  tartar,  and  one-sixth  of  a  grain  gum  trag- 
acanth in  each ;  these  should  also  be  kept  in  well-closed  bottles. 
The  one-grain  camphor  and  three-grain  quinine  pills  on  the  table 
contain,  in  addition  to  the  soluble  cream  of  tartar,  one-twelfth  of  a 
grain  gum  tragacanth  in  each.  The  gallic  acid  pill,  as  might  have 
been  expected,  is  large  but  hard,  keeps  well,  and  makes  a  more  satis- 
factory pill  than  when  glycerin  is  used ;  all  these  pills  are  firm,  dis- 
solve quickly  in  tepid  water,  and,  what  is  of  considerable  importance, 
present  a  good  appearance. 
I  thought  it  probable  that  by  boiling  trisnitrate  of  bismuth  in  a  so- 
lution of  soluble  cream  of  tartar  a  soluble  bismuth  pill  might  be  pre- 
pared, but  I  find  it  takes  seven  grains  of  the  dried  salt  to  dissolve  one 
grain  of  the  trisnitrate.  I  have,  however,  prepared  four-grain  pills  of 
this  body,  which  contain  hatf  a  grain  of  the  trisnitrate  in  each. — 
Pharm,  Journ.y  Lond.,  Nov.  4,  1871. 
OBSERVATIONS  ON  THE  COLOR  OF  FLUORESCENT  SOLU- 
TIONS.—NO.  II. 
By  Henry  Morton,  Ph.  D., 
President  of  the  Stevens  Institute  of  Technology. 
Since  the  publication  of  my  article  on  the  above  subject,*  I  have 
discovered  a  curious  action  which,  while  it  in  no  respect  affects  my 
*  See  American  Journal  of  Pharmacy,  1871,  Oct.,  463. 
