560  Oils  of  Winter  green  and  Birch.  {^ov^£%f: 
From  the  analytical  results  and  other  information  gathered  here 
and  there,  I  would  suggest  the  following  formula  : 
Sulphur  .  .  9  parts. 
Lampblack  or  powdered  charcoal  i  part . 
If  it  is  necessary  to  employ  antimony  sulphide,  the  following  for- 
mula gives  a  fairly  good  product : 
Sulphur  88  parts. 
Antimony  sulphide  12  " 
I  wish  here  to  kindly  thank  Messrs.  Ebert  and  Heinitsh  for  their 
useful  information  and  prompt  responses. 
THE  OILS  OF  WINTERGREEN  AND  BIRCH. 
By  Henry  Trimble. 
Contribution  from  the  Chemical  Laboratory  of  the  Philadelphia  College  of 
Pharmacy.    No.  148. 
In  the  year  18891  Mr.  Hermann  J.  M.  Schroeter  and  the  writer 
made  a  chemical  study  of  the  oils  of  wintergreen  and  birch.  Our 
results  were  criticised  soon  after  by  Dr.  F.  B.  Power,2  who  offered, 
in  the  same  article,  the  results  of  a  similar  study  conducted  by  him, 
which  results  differed  in  almost  every  particular  from  those  obtained 
by  us. 
Dr.  Power,  associated  with  Dr.  Clemens  Kleber,  has  recently3 
published  the  conclusions  reached  after  a  further  investigation  con- 
ducted by  them. 
In  this  second  study  the  authors  have  obtained  results  which  in 
many  respects  agree  with  those  obtained  six  years  ago  by  Mr. 
Schroeter  and  myself ;  yet  the  casual  reader  would  probably  think, 
on  examining  their  conclusions,  that  nearly  all  of  them  were  new. 
Since  writers  of  text-books  often  do  not  quote  recent  investigations, 
especially  where  there  have  been  some  differences  of  opinion,  simply 
because  they  do  not  see  comparative  statements,  I  have  thought 
that  a  concise  account  of  the  facts  as  they  now  exist  might  aid  some 
writers  to  quote  more  recent  views  than  those  of  Cahours  in  1843. 
In  making  the  following  comparison,  I  wish  it  distinctly  understood 
1  Am.Jour*  Pharm.,  61,  398. 
2  Pharmaceutische  Rundschau,  7,  283. 
3  Pharmaceutische  Rundschau,  13,  228. 
