296 
ON  THE  SOURCE  OF  BALSAM  OF  PERU. 
desirable  substitute  for  the  oils  used  for  that  purpose,  inasmuch 
as  has  been  just  stated,  it  is  less  gummy,  and  consequently  more 
easily  washed  out  when  the  wool  is  spun.  For  illuminating  pur- 
poses it  was  found  to  answer  admirably  when  burned  in  lamps 
that  are  provided  with  a  draft  by  chimneys,  giving  a  superior 
light  and  also  being  consumed  less  rapidly  than  sperm  oil.  In 
ordinary  lamps  the  wick  was  found  to  crust  slightly,  but  it  gave 
abrilliant  and  clear  light.  It  is  said  that  in  Cochin  China  it  is 
extensively  used  instead  of  olive  oil  for  the  purposes  of  illumi- 
nation. 
From  the  experiments  made  with  nut  oil  it  is  concluded  that 
it  will  answer  all  the  purposes  in  Pharmacy  to  which  other  oils 
are  applied,  except  in  the  preparation  of  lead  plaster;  and  as 
has  been  shown  in  some  of  the  preparations,  it  would  be  a  desir- 
able substitute.  As  it  can  be  obtained  at  about  90  cent3  per 
gallon,  it  is  likely  to  be  substituted  for  olive  oil,  and  it  would 
therefore  be  well  for  manufacturers  who  purchase  olive  oil  for 
making  lead  plaster,  to  examine  it  first  by  boiling  with  lith- 
arge, as  if  adulterated  with  nut  oil  it  will  be  found  not  to  form 
a  plaster  of  a  sufficient  degree  of  hardness. 
ON  THE  SOURCE  OF  BALSAM  OF  PERU. 
By  J,  Carson,  M.  D. 
Prof.  Wm,  Procter : 
Dear  Sir, — I  submit  to  your  inspection  a  letter  lately  re- 
ceived from  Dr.  Charles  Dorat,  of  La  Union,  Guatemala,  and 
if  you  think  proper  to  publish  it  in  the  American  Journal  of 
Pharmacy,  it  is  at  your  service.  To  me  it  is  interesting,  as  it 
more  specifically  designates  the  mode  of  obtaining  the  article 
known  as  Peruvian  Balsam.  From  this  it  appears  that  the 
article,  must  at  least  partially  be  empyreumatie  ;  and  from  being 
prepared  by  boiling,  is  modified  in  composition  so  as  to  be  very 
different  from  a  natural  exudation.  The  communication  agrees 
in  the  main  with  the  paper  published  in  the  American  Journal 
of  Pharmacy,  for  1851,  page  133,  from  the  London  Pharma- 
ceutical Journal,  by  Dr.  Pereira.  The  specimen  of  the  plant 
in  flower,  which  has  been  sent  to  me,  corresponds  with  the  de- 
scription given  by  Pereira,  and  I  have  not  the  least  doubt  of  its 
