162      ON  THE  MANUFACTURE  OF  PRUSSIATE  OF  POTASH.  ' 
The  feature  which  is  most  interesting  in  the  chemical  examina- 
tion of  the  bark,  is  the  presence  of  a  bitter  alkaloid,  soluble  in 
ether,  and  precipitable  as  a  white  hydrate,  from  its  solution  in 
acid  ;  of  this  I  have  assured  myself  by  two  experiments,  guard- 
ing very  especially  against  the  possibility  of  mistake  from  any 
source.  The  bark  contains,  in  addition,  a  large  percentage  (6 
per  cent.)  of  fragrant  wax,  as  well  as  some  fatty  matter.  Brandes 
obtained  from  the  Croton  Tiglium  a  crystallizable  substance  which 
lie  called  Crotonin,  and  thought  to  be  a  peculiar  alkaloid,  but 
this  was  brought  into  question  by  Weppen,  who  found  only  a 
magnesian  soap  with  an  alkaline  reaction,  f  The  alkaloid  which 
I  have  obtained,  yields  a  deep  green  color  with  chlorine  and  am- 
monia. The  proportion  in  the  bark  is  about  0.05  per  100  parts. 
The  taste  is  not  unlike  that  of  quinine  ;  but  it  appears  to  differ 
from  this  alkaloid  in  being  (apparently)  crystalline,  and  in  not 
affording  under  the  microscope  the  appearance  which  Herapath 
has  so  well  indicated  as  the  test  for  quinine, — neither  does  it 
answer  to  quinidine.  It  deserves  further  examination. — London, 
Pharm.  Jour.  Jan.  1855. 
MANUFACTURE  OF  PRUSSIATE  OF  POTASH. 
Mr.  Watson,  of  Leeds,  has  lately  suggested  some  improvements 
in  apparatus  for  the  manufacture  of  prussiate  of  potash.  These 
improvements  consist  in  so  constructing,  arranging,  and  combining 
apparatus  with  the  iron  pots,  in  which  the  animal  matter  is  com- 
bined with  the  fused  potash,  that  such  animal  matter  may  be  in- 
troduced into  the  pots  through  a  tube  or  passage  communicating 
with  the  lower  part  of  the  pots,  and  in  connecting  with  the  pots 
another  and  smaller  vessel,  in  such  manner  as  to  be  heated  by 
the  same  fire,  for  the  purpose  of  fusing  the  potash  previous  to- 
introducing  it  into  the  pots,  and  having  this  smaller  vessel  so 
connected  with  the  pots,  that  the  fused  potash  can  be  conveni- 
ently admitted  from  the  smaller  into  the  larger  vessel ;  or  such 
smaller  vessel  so  placed  in  connexion  with  the  larger  vessel,  that 
it  may  be  heated  by  the  same  fire,  and  moveable  in  such  manner 
that  the  fused  potash  may  be  transferred  out  of  it  into  the  larger 
vessel.  *  Also,  in  connecting  a  pipe  or  tube  with  such  pots  or 
f  Pereira,  Mem.  of  Mat.  of  Med.,  ed.  3.,  vol.  ii.,  part  1,  p.  1274. 
