PREPARATION  OF  BLUE  PILL,  ETC. 
161 
while  hot,  without  its  contents  being  displaced ;  and  on  cooling, 
the  solidification  is  still  more  complete.  Gentle  warmth  and  agi- 
tation restore  to  a  great  extent  its  fluidity,  but  solidification  is 
again  produced  upon  the  liquid  being  heated  to  266°.  Copaiba 
displays  no  such  phenomenon. 
According  to  Dr.  O'Shaughnessy,  when  Wood  Oil  is  heated 
in  a  retort,  a  yellowish  white,  crystallizable,  solid  substance, 
having  many  of  the  properties  of  benzoic  acid,  sublimes  into  the 
upper  part  of  the  vessel,  to  the  extent  of  about  one  per  cent,  of 
the  Wood  Oil  taken.  In  my  own  experiments,  I  have  not  de- 
tected any  of  this  substance.  It  is  true  that  when  Wood  Oil  is 
heated,  a  scanty,  opaque  white  sublimate  condenses  in  the  cooler 
part  of  the  vessel,  but  this  appears  to  arise  from  the  condensa- 
tion of  a  little  water  among  the  minute  drops  of  essential  oil, 
since  it  is  not  produced  if  the  Wood  Oil  has  been  previously  agi- 
tated with  some  fragments  of  dried  chloride  of  calcium. 
With  regard  to  its  medicinal  properties,  there  appears  to  be 
no  doubt,  from  an  extensive  set  of  experiments  instituted  by  Dr. 
O'Shaughnessy,  confirmed  by  trials  made  by  other  practitioners 
in  India,  that  Wood  Oil  is  nearly  equally  efficient  with  Copaiba, 
in  the  diseases  in  which  that  drug  is  indicated. f  It  may  be  ad- 
ministered as  an  emulsion,  or  in  pills  made  up  with  magnesia. 
Dr.  O'Shaughnessy  has  used  the  essential  oil  in  doses  of  from 
10  to  30  drops. 
From  the  close  similarity  of  Wood  Oil  to  Copaiba,  a  mixture 
of  the  two  may  be  anticipated ;  from  pure  Copaiba,  such  a  mix- 
ture will  probably  be  detected  by  a  difference  in  its  optical  pro- 
perties.— Pharm  Jour.  Jan.  1,  1856. 
THE  PREPARATION  OF  BLUE  PILL  AND  GREY  POWDER. 
By  W.  W.  Stoddart. 
The  preparation  of  these  two  most  important  articles,  when 
the  directions  of  the  Pharmacopoeia  are  strictly  followed,  is  a 
very  tedious  process,  so  much  so,  that  most  druggists  generally 
order  them  from  a  wholesale  house,  not  thinking  it  worth  their 
t  Bengal  Dispensatory  (1842),  pp.  222-224. 
11 
