ON  THE  USE  OF  BENZOLE. 
341 
I  must  caution  those  that  follow  this  process  to  beware  of  the 
blistering  property  of  the  benzole  solution  of  cantharidine  in  all 
its  stages.  Unless  great  care  be  used  severe  blisters  will  be  the 
painful  result. 
The  following  applications  of  benzole  have  not  yielded  quite 
such  satisfactory  results  as  the  foregoing,  but  still  such  as  to  en- 
courage us  to  persevere  in  ■  the  application  of  this  body  to  deli- 
cate chemical  manipulation,  and  to  prove  that  it  is  an  important 
addition  to  our  means  of  organic  research. 
Atropine  was  obtained,  though  not  in  distinct  crystals,  by  the 
following  method.  An  aqueous  extract  of  belladonna,  prepared 
with  great  care,  in  vacuo,  was  rubbed  with  sufficient  water  to 
soften  it ;  then  a  little  very  concentrated  solution  of  carbonate 
of  potassa  having  been  incorporated,  the  benzole  was  added,  and 
the  whole  well  rubbed  together.  After  two  or  three  quantities 
of  benzole  had  thus  been  rubbed  with  the  extract  they  were 
mixed  and  distilled ;  the  dark  oily  residuum  was  treated  with 
acetic  acid,  filtered,  and  precipitated  with  ammonia,  a  white  curdy 
precipitate  was  formed,  which,  however,  was  not  yet  pure,  as  it 
refused  to  crystallize  when  dissolved  in  alcohol  and  evaporated  :  a 
resinous  or  oily  matter  still  contaminated  it,  which  interfered 
with  its  purification.  This  subject  still  engages  my  attention, 
and  I  hope  at  a  future  opportunity  to  be  able  to  give  a  better 
account  of  the  matter. 
Extract  of  henbane,  prepared  with  equal  care,  was  treated  in 
a  similar  manner ;  the  acid  solution  of  the  oily  residuum  did 
not,  however,  give  a  curdy  precipitate  with  ammonia,  but  only 
a  slight  opalescence ;  however,  upon  shaking  the  liquid  with  an 
equal  bulk  of  ether,  separating  and  allowing  the  ether  to  evapo- 
rate very  slowly,  a  minute  quantity  of  crystals  were  on  one  oc- 
casion produced,  which  burnt  perfectly,  were  soluble  in  a  few 
drops  of  dilute  acetic  acid,  and  precipitated  again  as  a  white 
cloud  by  ammonia,  which  cloud  was  instantly  taken  up  by  being 
shaken  with  ether. 
I  next  turned  my  attention  to  the  so-called  sulphate  of  be- 
beerine  of  commerce.  It  was  treated  with  a  solution  of  caustic 
potassa,  and  then  with  benzole ;  the  benzole  being  distilled  off 
yielded  the  bebeerine  of  a  pale  straw  color,  but  in  very  small 
quantity.    It  was  soluble  in  acids  and  precipitated  by  alkalies, 
