A™ctober5905™'}    American  Pharmaceutical  Association.  489 
comparatively  low  temperatures.  From  its  ether  or  chloroform 
solution  the  solvent  may  be  evaporated  at  room  temperature  and 
the  residue  brought  to  constant  weight  over  sulphuric  acid  without 
loss  of  substance.  If  the  solvent  is  distilled  from  a  flask  and  the 
residue  dried  at  50c-6o°,  loss  by  volatilization  is  slight  and  a  prac- 
tically constant  weight  is  attained  in  twelve  to  twenty-four  hours. 
At  950  acetanilide  is  appreciably  volatile  even  when  contained  in  a 
narrow-necked  flask.  The  residue  obtained,  when  from  an  ether  or 
chloroform  solution  the  solvent  is  driven  off,  is  not  pure  acetanilide, 
and  if  loss  by  vaporization  is  guarded  against,  high  results  are  inva- 
riably obtained. 
Plant  Pig7ne?its,  with  Special  Reference  to  the  Quinhy drone 
Hypothesis  of  Plafit  Pigmentation.  By  I.  W.  Brandel  and  Edward 
Kremers.  This  monograph  is  the  outcome  of  several  years'  work, 
which  had  its  beginning  in  the  discovery  of  thymoquinone,  hydro- 
thymoquinone  and  thymoquinhydrone  in  the  oil  of  Monarda  fistu- 
losa.  The  introductory  part  consists  of  a  historical  review  of  the 
various  hypotheses  concerning  plant  pigments,  practically  all  of 
which  were  based  on  little  or  no  experimental  evidence  and  equally 
devoid  of  an  exact  chemical  basis.  The  first  half  of  the  paper  proper 
is  devoted  to  a  chemical  classification  of  all  known  plant  pigments 
of  known  structure  by  referring  them  to  their  underlying  hydrocar- 
bons, and  the  classification  of  the  latter  primarily  according  to  their 
degree  of  saturation.  Some  remarkable  analogies  have  been  re- 
vealed and  generalizations  as  to  color  and  constitution  are  given. 
The  second  half  is  devoted  to  a  botanical  classification  of  plant  pig- 
ments, which  not  only  gives  some  idea  of  the  scope  of  the  work  done, 
but  shows  analogies  that  should  be  helpful  in  indicating  the  way  for 
the  future  investigator.  Still  more,  long-known  facts  that  had  been 
waiting  for  a  rational  interpretation  are  understood  when  observed 
from  the  point  of  view  of  the  quinhydrone  hypothesis. 
A  Bottle  for  Keeping  Sterilized  Pharmaceutical  Preparations. 
By  Henry  Kraemer.  This  paper  will  appear  in  a  later  issue  of  the 
Journal. 
The  Approximate  Measures  of  the  U.S.  P.  By  M.  I.  Wilbert. 
The  approximate  equivalents  for  popular  dose  measures,  directed  in 
the  eighth  decennial  revision  of  the  U.S. P.,  appear  to  be  based  on 
the  assumption  that  the  metric  system  of  weights  and  measures  is 
closely  related  to,  or  dependent  on,  the  weights  and  measures  now 
