Am.  Jour.  Pharm.  \ 
August,  1883.  j 
Tinctura  Ferri  Chloridi. 
387 
The  composition  of  these  compounds  with  the  alkalies,  in  which  the 
hydrogen  atom  of  the  phenol  group  of  methyl  salicylate  is  replaced 
by  potassium,  sodium,  etc.,  and  their  decomposition  by  the  action  of 
an  acid  with  the  regeneration  of  the  original  oil,  may  perhaps  be  more 
clearly  seen  when  expressed  by  an  equation,  as  follows : 
OK  OH 
/  / 
CeH,  +    HCl   =    CfiH,  +  KCl. 
CO— OCH3  CO— OCH3 
It  is  worthy  of  note  that  the  specific  gravity  of  oil  of  gaultheria,  as 
stated  in  the  United  States  Pharmacopoeia  (1880),  corresponds  precisely 
with  that  of  oil  of  birch,  while  the  specific  gravity  of  an  authentic 
specimen  of  oil  of  gaultheria  in  the  possession  of  Prof.  Maisch  was 
found  to  be  but  1-0318  at  22°C. 
The  lower  specific  gravity  of  oil  of  gaultheria  may  easily  be 
explained  by  the  presence  in  the  latter  of  a  terpene  which  is  lighter' 
than  water. 
The  results  obtained  by  the  present  investigation  may,  therefore,  be 
briefly  summarized  as  follows  : 
I.  The  volatile  oil  of  birch  is  not  identical  with  the  oil  of  gaulthe- 
ria, in  that  it  consists  entirely  of  salicylate  of  methyl,  and  contains  no 
terpene. 
II.  The  specific  gravity  of  oil  of  gaultheria  is  not  1*180,  as  stated 
in  the  United  States  Pharmacopoeia,  but  1*0318  ;  the  former  being  the 
specific  gravity  of  oil  of  birch,  which,  as  is  known,  is  often  indiscrim- 
inately sold  and  employed  as  oil  of  gaultheria. 
In  conclusion,  the  writer  desires  to  state  that  he  has  commenced  the 
analysis  of  pure  oil  of  gaultheria,  and  that  the  terpene  which  it  con- 
tains, but  of  which  at  present  so  little  is  known,  will  be  submitted  to 
further  investigation. 
TINCTURA  FERRI  CHLORIDI. 
By  Mimms  William  Coleman,  Ph.G. 
From  an  Inaugural  JEssay. 
As  much  discrepancy  of  opinion  exists  regarding  the  desirability  of 
retaining  the  alcohol  in  the  preparation  of  Tinct.  ferri  chloridi,  it  has 
seemed  of  interest  to  institute  a  series  of  experiments  bearing  upon 
this  point,  and  also  to  extend  the  investigation  to  the  determination  of 
the  result  of  other  influences  upon  the  preparation. 
