ON  THE  PRESERVATION  OF  LEECHES. 
323 
and  water  according  to  the  author  are — 1,  the  lower,  ether  dis- 
solved in  hydrate  of  tannic  acid  ;  2,  the  second,  the  syrupy  liquid 
of  hydrate  of  tannic  acid  dissolved  in  etherated  water ;  and  3, 
the  same  composition  containing  the  fatty  and  resinous  matter. 
— Qhem.  News,  London,  March  17,  1860. 
ON  THE  PRESERVATION  OF  LEECHES. 
By  J.  Mill  Frodsham,  M.  D., 
Physicaii  to  the  Farringdon  Dispensary. 
Hospitals  and  vendors  have  endeavored  to  derive  advantage 
from  leeches  by  making  them  serve  several  times,  and  especial- 
ly by  preserving  them  ;  yet  I  believe  even  now  a  leech  is  seldom 
employed  twice,  the  mode  adopted  and  recommended  in  all  books 
for  cleaning  them  after  they  have  been  used  being  generally 
fatal.  When  I  was  house-surgeon  to  the  County  Infirmary, 
Carlisle,  I  made  numerous  experiments  to  see  how  often  and 
how  long  leeches  could  be  employed  and  preserved  without  death ; 
for  this  purpose  a  small  glass  vessel  was  used,  in  the  bottom  of 
which  was  placed  about  three  inches  of  peaty  earth,  and  twelve 
leeches,  and  then  half  filled  with  water,  the  mouth  being  secured 
with  a  coarse  rag.  These  leeches  lived  in  health  for  a  year  with 
only  one  or  two  deaths,  many  of  them  being  employed  twice  in  one 
day ;  but  after  being  used,  instead  of  putting  them  in  salt,  or 
vinegar  and  water,  as  usually  done,  they  were  placed  for  a  few 
seconds  in  the  camphor  mixture  of  the  Pharmacopoeia,  and  af- 
terwards washed  in  cold  water,  avoiding  too  much  contact  with 
the  hand.  But  the  apparatus  par  excellence  for  preserving 
leeches  is  the  one  introduced  by  M.  Vayson,  an  eminent  French 
breeder,  and  called  by  him  the  "  Domestic  Marsh."  This  con- 
sists  simply  of  an  earthenware  vessel  in  the  form  of  a  truncated 
cone  reversed,  the  lower  extremity  of  which  is  pierced  with  a 
few  holes  sufficiently  narrow  not  to  allow  the  leech  to  pass 
through.  This  vessel  is  filled  with  turfy  earth,  the  leeches  are 
placed  in  it,  and  they  soon  instal  themselves  as  well  as  they  can ; 
then  the  orifice  is  closed  with  a  coarse  cloth.  If  desired  to  be 
sent  to  a  great  distance  the  earth  is  wetted  in  all  its  thickness, 
and  the  vessel  packed  in  a  basket  or  box.  If  desired  to  pre- 
serve them  on  the  same  spot,  the  lower  end  of  the  vessel  is  placed 
