Am,j^i894arm*}  Revision  of  the  U.  S.  Pharmacopeia.  15 
ceutical  preparations.  Neither  the  percentage  of  water  allowable 
in  opium  nor  the  yield  of  extract  is  given. 
The  introduction  of  Pepsin  is  accompanied  by  an  official  descrip- 
tion sufficiently  elastic  to  admit  all  the  varieties  of  pepsin  in  the 
market,  providing  that  they  possess  the  required  digestive  value. 
There  is  a  lack  of  definiteness  in  a  product  that  may  be  either 
*'  white,  yellowish-white,  pale  yellow,  or  yellowish  ;  "  may  be  either 
"  an  amorphous  powder,  grains  or  scales;"  may  be  either  "  soluble 
or  only  partly  soluble,"  and  may  be  "  opaque  or  translucent." 
Would  it  not  have  been  more  in  accordance  with  pharmacopceial 
exactness  to  have  introduced  two  pepsins,  one  in  powder,  the  so- 
called  insoluble,  and  the  other  in  grains  or  scales,  the  so-called 
soluble  ?  The  properties  of  each  could  have  been  definitely  fixed 
and  the  former  directed  for  preparing  the  saccharated  pepsin  and 
dispensing  in  powders,  the  latter  for  solutions.  The  statement  in 
the  assay  process  that  "  100  cc.  of  the  liquid  will  contain  o-2  cc.  of 
absolute  hydrochloric  acid  and  0-00335  §m-  °f  the  pepsin  to  be 
tested  and  98  cc.  of  water"  is  a  self-apparent  error,  as  necessarily 
there  must  be  somewhat  more  than  98  cc.  of  water. 
The  use  of  the  various  purified  liquid  petroleum  products  so 
largely  introduced  as  proprietary  articles  has  necessitated  the  official 
recognition  of  a  Liquid  Petrolatum.  There  is  too  much  variation 
allowable  in  the  official  description  of  color  and  gravity  of  this  prod- 
uct. The  requirements  of  the  Pharmacopoeia  Germanica  for  paraf- 
finum  liquidum  ("  without  color,  clear,  non-fluorescent,  *  *  * 
about  -88o  sp.  gr.")  should  have  been  adopted.  The  statement 
that  it  is  "  readily  soluble  in  fixed  oils  "  must  be  questioned  as  it  is 
nearly  insoluble  in  castor  oil. 
The  two  terms  Soft  Petrolatum  and  Hard  Petrolatum  replace  the 
Petrolatum  of  1880.  This  change,  I  presume,  has  been  made  to 
define  the  products  suitable  for  different  climates  and  uses.  Fluor- 
escence in  these  products  is  due  to  impurities  remaining  and  is  an 
indication  of  the  degree  of  purification  the  product  has  been  sub- 
jected to.  I  would  suggest  that  in  the  official  description  "more  or 
less  fluorescent  "  should  be  changed  to  "  nearly  or  quite  free  from 
fluorescence."  The  melting  point  is  given  for  the  soft  at  400  to 
450  C.  and  for  the  hard  45 0  to  510,  so  that  there  is  an  intermediate 
melting  point,  45 °,  where  the  petrolatum  may  be  either  hard  or  soft. 
The  melting  point  for  the  hard  petrolatum  should  be  480  to  520  C. 
