286 
EDITORIAL. 
tracted  the  attention  of  the  Committee,  and  they  wisely  determined  to 
settle  this  point  before  proceeding  with  the  construction  or  revision  of  the 
formulas.  The  Dublin  Pharmacopoeia  having  already  adopted  the  avoir- 
dupois weight,  and  the  opinion  in  favor  of  having  but  one  kind  of  weight 
for  selling  and  mixing  prevailing,  was  the  cause  of  the  adoption  of  the 
commercial  weight  for  pharmacopoeial  purposes,  but  to  avoid  confusion,  the 
only  terms  in  which  the  weights  of  the  Pharmacopoeia  are  expressed  are 
the  grain,  ounce  and  pound. 
Our  readers  have  already,  by  previous  notices,  been  made  acquainted 
with  the  facts  bearing  on  this  subject,  (see  vols,  xxxiv.  and  xxxv.)  and 
we  will  not  further  remark  upon  it,  except  to  wish  that  our  own  Pharma- 
copoeia Committee  had  been  induced  to  adopt  the  same  standard.  The 
first  part  of  the  British  Pharmacopoeia,  entitled  Materia  Medica,  differs 
from  all  previous  editions,  of  that  and  of  our  own,  in  giving  under  each 
head  the  characters  of  the  substance,  as  well  as  tests  for  its  purity.  The 
following  will  give  the  idea  : 
«  ACACIA.  Gum  Arabic. 
One  or  more  undetermined  species  of  Acacia,  Linn. 
A  gummy  exudation  from  the  stem ;  collected  chiefly  in  Cor- 
dofan  in  Eastern  Africa,  and  imported  from  Alexandria. 
Characters. — In  spheroidal  tears  from  half  an  inch  to  an  inch  in  length, 
nearly  white,  and  opaque  from  numerous  minute  cracks,  or  in  shining 
fragments;  brittle,  bland  and  mucilaginous  in  taste,  soluble  in  cold 
water.    The  solution  forms,  with  subacetate  of  lead,  an  opaque  white  jelly. 
Test.  The  powder  does  not  become  blue  on  the  addition  of  solution  of 
iodine. 
Preparation.  Mucilago." 
Another  peculiarity  of  this  part  is  the  fact  that  it  includes  a  large  num- 
ber of  substances  which  are  usually  considered  only  in  the  second  part  of 
the  book.  For  instance,  spirit  of  nitrous  ether  and  solution  of  acetate  of 
ammonia  are  each  in  the  officinal  list,  yet  they  are  also  among  the  prepar- 
ations, and  so  of  a  large  number  of  other  preparations,  more  especially 
chemical  substances.  In  some  cases  these  short  descriptions  are  useful  in 
determining  at  once  what  the  Pharmacopoeia  intends.  Many  of  the  tests 
appended  seem  wholly  inadequate  to  determine  the  genuineness  and  purity  ' 
of  the  drugs.  Thus,  Oil  of  Lemon  is  thus  characterized  : — 
"  Color  pale  yellow,  odor  agreeable,  taste  warm  and  bitter." 
Others  are  peculiar,  as  that  for  Resin  of  Guaiacum,  to  which  the  follow- 
ing test  is  appended  : — 
«  Test.  A  solution  in  rectified  spirit  strikes  a  clear  blue  color  when 
applied  to  the  inner  surface  of  a  paring  of  raw  potato 
The  reaction  here  is  between  the  glutinous  matter  of  the  potato  and  the 
guaiac  ;  and  is  a  characteristic  test.  Whenever  the  chemical  nature  of  the 
substance  admits,  its  chemical  formula  is  given.    Thus,  "  Beberiae  Sulphas, 
