NOTE  RELATIVE  TO  THE  EFFECTS  OF  ATEOPIA.  203 
ment,  which  is  an  unsatisfactory  preparation,  requires  a  great 
deal  of  attention,  and  is  also  tedious  and  troublesome  to  make, 
besides  changing  in  color  and  consistence. 
Crystallized  nitrate  of  mercury  is  prepared  by  placing  four 
hundred  grains  of  mercury  in  a  small  capsule  and  pouring  on  it 
three  hundred  grains  of  pure  nitric  acid  (sp.  gr.  1-42).  The 
mixture  should  be  stirred  occasionally  with  a  glass  rod  until 
nearly  all  the  mercury  is  dissolved,  when  the  rod  should  be  re- 
moved and  the  vessel  and  solution  allowed  to  stand  until  cold. 
Clear  crystals  will  soon  appear  in  the  form  of  plates  overlapping 
each  other.  About  five  hundred  and  sixty  grains  of  the  dried 
salt  is  obtained,  and  about  ten  grains  of  mercury  remains  un- 
dissolved. 
Crystallized  nitrate  of  mercury  is  soluble  in  glycerin,  slightly 
soluble  in  alcohol,  ether  and  acetic  acid.  Theoretically  three 
hundred  and  forty-four  grains  of  citrine  ointment  is  equivalent 
to  forty-three  grains  of  crystallized  nitrate  of  mercury.  As  the 
salt  is  quite  soluble  in  glycerin  the  best  manner  of  using  it  as  a 
substitute  for  citrine  ointment  would  be  to  dissolve  forty-three 
grains  in  five  drachms  of  glycerin,  which  is  equivalent  in  pro- 
portion to  that  ointment.  (But  probably  in  practice,  owing  to 
the  soluble  condition  of  the  mercurial  salt,-  it  would  be  found 
much  more  active.)  Dr.  Neill  has  used  it  in  the  proportion  of 
twenty  grains  in  a  fluidounce  of  glycerin,  which  answered  his 
purposes  better  than  citrine  ointment.  The  crystals  made  with 
chemically  pure  nitric  acid  (sp.  gr.  1*42)  become  dry  and  hard 
and  will  keep  for  a  long  time,  while  those  that  are  prepared  with 
common  aquafortis  become  deliquescent.  The  salt  should  be 
kept  in  a  glass  stoppered  bottle. 
NOTE  RELATIVE  TO  THE  EFFECTS  OP  ATROFIA. 
By  Dr.  S.  R.  Percy. 
[In  quoting  Dr.  Percy's  statement  relative  to  the  use  of 
atropia  for  toothache  we  appear  to  have  conveyed  a  wrong  im- 
pression in  reference  to  its  tendency  to  accumulative  efiects 
when  administered  at  intervals.  The  following  note  will  set  the 
matter  right. — Ed.  Am.  Jour.  Pharm.] 
