AmM^hfmim'}    Estimation  of  Ash  in  Various  Drugs.  137 
was  largely  the  peculiar-odored  gas  which  is  under  examination. 
It  will  be  seen  that  the  gases  increase  and  decrease  quite  uniformly. 
The  variations  which  occur  were  undoubtedly  due  to  the  uneven 
application  of  heat. 
In  order  to  determine  whether  or  not  the  nitrogen  estimated  as 
such  was  pure,  the  hydrocarbons  were  removed  by  combustion  with 
pure  oxygen,  and  the  residue  sparked  with  excess  of  oxygen  over 
potassium  hydrate  until  no  further  change  took  place.  About  200 
c.c.  of  the  residue  were  taken,  and  at  the  end  of  the  process  there 
remained  2-6  c.c.  of  gas,  which  remained  unchanged  after  several 
days'  sparking  gave  the  spectrum  for  argon.  No  satisfactory  ex- 
planation for  this  spectrum  can  as  yet  be  given.  The  process  is 
being  repeated  with  larger  quantities  of  gas.  It  seems  impossible 
that  this  quantity  could  have  come  from  the  air  which  was  left  after 
exhausting  the  retort  with  a  mercury  pump. 
University  of  Minnesota, 
Minneapolis,  Minn. 
^ESTIMATION  OF  ASH  IN  VARIOUS  DRUGS. 
By  Charges  H.  LaWau,. 
Sub-Committee  of  Research  of  the  United  States  Pharmacopceial  Committee 
of  Revision. 
The  subject  of  the  inorganic  constituents  of  plants  has  received 
very  little  attention  in  itself ;  the  existing  data  are  scattered,  and,  in 
many  cases,  obtainable  only  after  a  laborious  search.  One  exten- 
sive work  on  the  ash  in  plants  was  published  in  1871.1 
This  concerns  itself  mainly,  however,  with  the  per  cent,  of  ash  in 
various  agricultural  products.  The  work  is  in  very  few  libraries  in 
this  country,  and  it  was  due  to  the  kindness  of  Professor  Trimble 
that  the  author  was  enabled  to  consult  it  before  tabulating  his 
results  upon  this  subject. 
Works  on  materia  medica  usually  contain  a  list  of  the  proximate 
organic  constituents  of  each  plant  considered ;  percentages  of  these 
constituents  are  only  given  in  few  cases,  and  then  with  no  reference 
to  the  authority  whose  figures  are  used.  This  is  often  unsatisfactory, 
1 1871,  Aschen-analysen  von  landwirthschaftlichen  Produden,  Fabrikabfiilien 
und  wildwachsenden  Pflanzen.    Dr.  Emil  Wolf. 
