376        Pennsylvania  Pharmaceutical  Association.  {Kmkl^t*m§m' 
maceutical  knowledge,  and  it  can,  therefore,  be  truly  said,  that  the 
Eighth  Revision  of  the  United  States  Pharmacopoeia  has  furnished, 
after  great  labor,  standards  for  manufacturer's  goods,  but  it  has  not 
neglected  its  no  less  important  duty,  that  of  furnishing  a  reliable 
pharmacist's  guide. 
Doses  in  the  United  States  Pharmacopoeia  of  1900. 
By  Clement  B.  Lowe,  M.D. 
The  author  states  his  disinclination  to  join  those  who  criticize 
simply  for  the  sake  of  criticism,  but  desires  to  call  attention  to  a 
few  facts  in  connection  with  the  feature  of  doses  in  the  Pharma- 
copoeia. He  states  that  this  is  the  second  time  that  doses  have  been 
included  in  the  United  States  Pharmacopoeia,  as  they  were  previously 
given  in  1830,  when  the  doses  of  Materia  Medica  articles  alone 
were  given.  After  tabulating  a  number  of  specific  instances,  the 
author  concludes  that  the  doses  as  given  in  the  present  Pharmaco- 
poeia are  rather  less  than  the  average  as  given  by  other  authorities. 
He  concludes  by  making  a  few  comments  on  some  of  the  changes 
in  preparations  and  titles,  and  praises  the  general  excellency  of 
the  work. 
Laboratory  Notes. 
By  Charles  E.  Vanderkleed. 
Spirit  of  Nitrous  Ether.  The  author  answers  the  query  as  to 
whether  the  spirit  prepared  from  concentrated  nitrous  ether  meets 
the  requirements  of  the  Pharmacopoeia  for  strength  in  the  affirmative 
with  the  proviso  that  the  proper  precautions  must  be  taken.  He 
states  that  he  has  never  found  a  sample  of  the  concentrated  nitrous 
ether  under  strength,  but  that  carelessness  in  diluting  would  result 
in  an  inferior  preparation.  The  best  method  of  diluting  the  spirit 
is  to  thoroughly  chill  the  bottle  containing  the  concentrated  nitrous 
ether,  and  then  open  it  with  the  neck  below  the  surface  of  the 
alcohol,  which  should  be  of  slightly  less  volume  than  that  neces- 
sary to  dilute  the  whole  quantity  of  the  bottle.  By  then  making 
an  assay,  using  an  inverted  burette  for  a  nitrometer,  uniform  results 
can  be  obtained.  He  states  that  no  allowance  is  made  for  vapor 
tension  in  the  U.S  P.  calculations  of  the  ethyl  nitrate  strength  of 
this  preparation,  which  correction  would  make  the  result  slightly 
lower.    The   author  criticizes  the  U.S.P.  pepsin  assay  by  stating 
