PURIFICATION  OF  BITTER  ALMOND  OIL.  435 
cannot  be  concerned  in  building  up  the  fabric  of  the  body,  nor 
can  it  by  its  combustion  contribute  to  the  maintenance  of  ani- 
mal heat.  This  is  surely  an  important  conclusion  to  have  ar- 
rived at.  The  weak  point,  however,  in  the  arguments  adduced 
against  the  value  of  alcohol  as  a  respiratory  food,  is  the  small 
quantity  of  it  which  the  experimenters  have  been  able  to  extract 
from  the  various  searetions.  It  is  possible  that,  by  more  deli- 
cate modes  of  investigation,  and  by  the  use  of  more  subtile  tests, 
a  much  larger  proportion  may  be  detected  ;  but  we  are  inclined 
to  think  that,  until  some  such  result  is  obtained,  physiologists 
will  not  be  disposed  to  abandon  their  views  as  to  the  oxidizable 
nature  of  the  substance. — Lon.  Pharm.  Journ.  May^  1861,  from 
Br.  Med.  Journ. 
ON  THE  COMMEKCIAL  PURIFICATION  OF  BITTER  ALMOND  OIL, 
By  John  S.  Blockey. 
The  poisonous  nature  of  this  substance  in  its  crude  state  war- 
rants the  conclusion  that  some  method  of  perfectly  freeing  it 
from  prussic  acid  or  combined  cyanogen  should  be  universally 
adopted,  either  in  its  first  formation  from  the  almonds,  or  in  the 
subsequent  rectification. 
Whether  even  then  it  is  quite  harmless  is,  I  think,  yet  to  be 
proved,  and  the  experiments  detailed  below  tend  to  show  that  it 
possesses  very  powerful  properties,  although  not  so  poisonous  as 
the  crude  oil.  Possibly,  like  many  essential  oils,  it  may  be 
found  available  in  medicine.  Gerhardt  states  that  the  oxide  of 
mercury  will  free  the  crude  oil  from  cyanogen,  but  I  have  re- 
peatedly tried  the  eflficacy  of  this  agent  both  alone  and  with 
water  at  various  temperatures  and  during  various  durations  with- 
out any  success.  I  also  assured  myself  that  the  HCy  is  not  in 
a  free  state,  for  no  effervescence  takes  place  on  the  addition  of 
NaO  C02  either  in  solution  or  otherwise.  I  next  tried  caustic 
potassa,  but  the  only  effect  was  to  produce  a  quantity  of  benzo- 
ate  of  potassa  equivalent  to  the  amount  of  alkali  employed. 
The  hydrated  oxide  of  mercury  appears  to  have  no  action.  I 
concluded,  therefore,  that  some  plan  must  be  adopted  to  free 
the  cyanogen  from  the  oil,  which  would  possess  sufficient  affinity 
