172 
ON  MEDICINAL  EXTRACTS,  ETC. 
hemlock  was  first  ordered,  but  here  the  whole  plant  was  directed 
to  be  taken,  then  bruised,  and  the  juice  expressed  and  evapo- 
rated with  care  ;  then,  in  1809,  these  preparations,  which  had 
previously  been  styled  inspissated  juices,  were  installed  as  ex- 
tracts, and  the  hemlock  (together  with  aconite,  belladonna,  and 
hyoscyamus,  now  for  the  first  time  introduced,)  were  all  ordered 
to  be  sprinkled  with  water  before  pressing  out  the  juice.  But 
for  reasons  with  which  we  are  not  acquainted,  the  leaves  only 
were  ordered  to  be  employed.  However,  Dr.  Powell,  the  autho- 
rized translator  of  that  edition,  is  by  no  means  explicit  about  the 
matter,  for  in  his  remarks  on  these  extracts,  he  says:  "  The  tex- 
ture of  the  plant  is  first  destroyed  by  bruising,  and  its  juice  ex- 
pressed is  then  evaporated."  The  College  also  directed  that  a 
small  quantity  of  rectified  spirit  should  be  sprinkled  on  all  the 
soft  extracts.  The  Pharmacopoeias  of  1824  and  1836  followed 
exactly  the  steps  of  their  predecessors,  and,  in  the  latter  edition, 
the  translator  adds  to  the  remarks  of  Dr.  Powell  just  quoted,  the 
words,  "  to  prevent  its  becoming  mouldy." — Lond.  Pharm.  Jour., 
Dec.  1861. 
[On  the  reading  of  this  paper  an  interesting  discussion  ensued,  which 
is  too  long  fur  insertion  entire.  The  following  outline  of  what  was  said  is 
abridged  from  the  published  account. — Ed.  Am.  Jour.  Pharm.~\ 
Mr.  Deane  had  some  experience  in  making  extracts  of  juices,  and  found 
them  to  keep  well  if  evaporated  without  coagulating  the  albumen  ;  but  if 
evaporated  below  boiling,  if  sufficient  to  coagulate  the  albumen,  yet  the 
presence  of  the  latter  in  a  coagulated  state  would  cause  mouldiness.  This 
was  not  so  if  boiling  was  resorted  to.  He  had  found  extracts  prepared  in 
vacuo  to  spoil  from  the  same  causes,  viz  : — the  partially  coagulated  but  un- 
cooked albumen.  A  somewhat  analogous  result  occurred,  with  some  other 
extracts,  as  liquorice  and  poppies,  when  made  at  a  low  temperature,  as  on 
keeping  they  underwent  a  sort  of  fermentation  and  gave  off  gas,  which 
caused  the  swelling  of  the  mass.  Much  of  the  efficiency,  elegance  and  per- 
manence of  green  extracts  depended  on  the  proper  condition  of  the  plants 
when  gathered,  and  at  the  time  of  operating  ;  especially  was  it  objection- 
able to  have  the  herbs  to  heat  by  lying  in  masses  after  being  gathered. 
Plants  gathered  too  early  were  more  albuminous  and  less  active.  The  in- 
florescence should  be  one-third  over  when  gathered.  At  this  age  plants 
yielded  extracts  of  the  best  consistence.  Mr.  Deane  concluded  by  some 
remarks  to  young  men,  urging  on  their  attention  the  importance  of  botanic 
studies. 
Mr.  Cracknell  had  for  some  years  paid  much  attention  to  the  preparation 
