90  Examination  of  Cascara  Sagrada.  {^'^'Tehl'mH''"^' 
and  a  microscopical  examination  indicates  the  presence  of  a  substance, 
insoluble  in  water,  of  an  oily  or  resinous  behaviour,  and  also  crystals 
of  the  bitter  substance  referred  to.  This  oily,  or  resinous  body,  seems 
to  be  an  excellent  solvent  for  the  bitter  principle,  inasmuch  as  on  cool- 
ing, fine  crystals  may  be  seen  distributed  through  it.  It  is  evident 
from  the  behaviour  of  this  solution  that  the  ferment  has  been  sepa- 
rated, and  it  is,  therefore,  precipitable  by  sub-acetate  of  lead. 
We  do  not  wish  to  be  understood  as  supposing  or  claiming  that  this 
ferment  acts  directly  in  producing  a  decomposition  of  the  glucoside, 
because  such  is  not  the  case.  The  ferment  simply  is  instrumental  in 
generating  vegetable  acids,  and  these  latter  are  the  direct  agents  en- 
gaged in  the  decomposition.  A  great  step  in  advance  will  have  been 
made  also,  by  the  recognition  of  the  fact  that  these  changes  can  take 
place  in  the  cold,  at  ordinary  temperatures,  in  the  human  stomach,  in 
the  percolator,  and  even  in  the  air-dried  bark  itself,  the  latter  to  all 
appearances  being  in  a  decidedly  quiescent  condition.  We  must  not 
forget  that  all  the  conditions  are  present,  even  to  the  extent  of  the 
necessary  moisture. 
An  ultimate  analysis  of  the  glucoside  as  well  as  the  bitter  princi- 
ple will  follow  shortly. 
The  glucose,  which  is  present  in  varying  proportions,  according  to 
the  age  of  the  bark,  plays  a  very  important  part  in  the  pharmacy  of 
cascara.  As  a  medicinal  agent  it  is  certainly  inert  in  common  with 
vegetable  albumen,  the  starches,  etc.,  and  is  even  capable  of  producing 
much  mischief  by  undergoing  the  process  of  fermentation  under  favora- 
ble conditions.  That  the  glucose  is  the  active  element  in  producing 
the  very  undesirable  "  falling,"  as  referred  to  by  Mr.  Butterfield,  in 
the  Pharmaceutical  Journal  and  Transactions,  1887,  p.  473,  is  very 
evident ;  that  an  extract  containing  a  liberal  quantity  of  glucose  may, 
in  the  process  of  manufacture  into  a  pill,  gather  on  its  surface  a  small 
army  of  ferment  germs  with  the  natural  result,  will  not  be  denied.  The 
glucose  decomposes  into  alcohol  and  carbonic  acid,  and  it  is  not  a  mat- 
ter of  wonder  that  the  pills  get  soft.  It  may  be  possible  to  destroy 
these  germs  by  the  application  of  an  alcoholic  varnish,  but  we  would 
respectfully  submit  our  opinion  that  it  would  be  a  much  more  scientific  ' 
method  to  remove  the  inert  glucose  and  avoid  the  presentation  of  bullets. 
The  traces  of  ammonia  which  we  have  been  able  to  find  remaining 
in  the  bark,  indicate  to  us  that  this  ingredient  has  undoubtedly  a  dis- 
tinct function,  which  appears  to  us  as  that  of  rendering  the  resins  solu- 
