ON  SOME  PREPARATIONS  OF  THE  U.  S.  PHARMACOPCEIA.  211 
Diluted  nitro- muriatic  acid.  The  object  of  this  preparation 
is  to  facilitate  the  dispensing  and  administration  of  the  acid, 
•which  in  its  undiluted  state  has  been  the  cause  of  unpleasant 
accidents,  from  the  sudden  escape  of  enclosed  chlorine,  when 
the  bottles  are  opened  for  use.  The  necessity  of  retaining  the 
undiluted  acid  is  not  very  apparent,  unless  it  had  been  used  as 
a  step  in  the  process  for  the  diluted  acid,  which  it  has  not. 
Acidum  Phosphoricum  Dilutum.  This  process,  which  is 
analogous  to  that  of  the  late  London  Pharmacopoeia,  in  its  re- 
sults differs  in  the  apparatus  used,  and  is  essentially  the  process 
of  Messrs.  Andrews  &  Thompson,  of  Baltimore,  published  in 
the  Maryland  Journal  and  Transactions,  for  Sept.  1,  1858,  and 
republished  in  this  Journal,  vol.  xxx,  page  525.  The  merit  of 
the  process  consists  in  the  use  of  a  porcelain  capsule,  in  lieu  of 
a  glass  retort.  The  inverted  dish,  recommended  by  Messrs. 
A.  &  T.,  is  very  properly  substituted  by  a  glass  funnel  in  the 
officinal  process,  •which,  while  equally  safe,  renders  the  process 
observable,  and  in  fact  converts  the  capsule,  for  the  time,  into 
a  glass  matrass. 
In  the  second  process,  wherein  the  solution  is  made  from  gla- 
cial phosphoric  acid,  the  addition  of  nitric  acid  is  to  facilitate 
the  conversion  of  the  glacial  into  tribasic  phosphoric  acid,  as 
recommended  by  Mr.  Maisch,  (see  vol.  xxxiii.  page  385,  of 
Amer.  Jour.  Pharm.)  an.d  which  is  much  more  slowly  effected 
by  ebullition  alone. 
The  Diluted  Mineral  Acids.  It  will  be  observed  that  the 
strength  of  the  diluted  muriatic,  nitric  and  sulphuric  acids,  has 
been  somewhat  changed  ;  all  of  them  are  slightly  weakened. 
The  change  in  strength  was  caused  by  employing  weight  instead 
of  measure  for  the  acids,  and  by  making  each  process  yield  just 
a  pint.  According  to  Mr.  A.  B.  Taylor,  the  ratio  of  the  old 
and  new  diluted  acids  is  as  follows : 
Ph.  1850.  Ph.  1860. 
Diluted  muriatic  acid,        2114  grs.  1920  grs.  per  pint. 
Diluted  nitric  acid,  1479  "  1440  "     "  « 
Diluted  Sulphuric  acid,  ratio  not  stated  but  nearly  equal. 
Acidum  Sulphurosum.  This  formula,  which  is  nearly  that 
in  Wittstein's  Pharmaceutical  Chemistry,  I  have  frequently 
