^"Mivch^im.'}       Preservation  of  Vaccine  Crusts,  105 
formula  for  compound  syrup  of  squill  read  thus  :  "  Add  sufficient 
boiling  water ^  through  the  strainer  to  make  it  {the  hot  syrup)  measure 
three  pints  "  (while  hot?)  In  view  of  the  tartar  emetic,  the  design  of 
the  formula  must  be  to  make  the  syrup  measure  three  pints  when 
oold^  but  a  fair  interpretation  of  the  directions  cannot  mean  that. 
Now  it  is  plain  that  three  pints  of  hot  syrup  will  not,  upon  cooling, 
be  three  pints  of  cold  syrup,  admitting  that  no  evaporation  takes 
place  in  the  act ;  but  most  commonly  a  considerable  evaporation 
will  take  place  during  the  process,  and  of  necessity  a  crystallization 
of  sugar  takes  place.  The  fault  is  even  worse  in  the  formula  for 
syrup  of  seneka.  The  directions  read  :  "  Filter,  and,  havirig  added 
the  sugar,  dissolve  it  with  the  aid  of  a  gentle  heat  and  strain  the  solu- 
tion while  hot.''  No  account  is  taken  of  the  loss  of  liquid  in  filtering, 
nor  of  evaporation  in  dissolving  the  sugar.  If  the  directions  are 
followed  'precisely,  in  such  cases,  crystallization  will  inevitably  take 
place,  even  if  the  amount  of  sugar  prescribed  is  not  a  little  too  great, 
as  I  am  of  opinion  it  is  in  the  two  first  of  the  syrups  herein  discussed. 
I  believe  that  in  practice  twenty-nine  troyounces  would  be  found  to 
answer  as  well  as  thirty  troyounces,  or  a  proportional  reduction  of 
other  quantities. 
Nashville,  Tenn.,  Jany.  24,  1871. 
PRESERVATION  OF  YACCINE  CRUSTS. 
By  David  Stewart,  M.  D. 
Vaccine  lymph  may  be  preserved  during  all  the  summer  months,  in 
any  climate,  by  the  following  expedient,  which  I  devised  several  years 
since  : — Immerse  them  in  mercury,  and  keep  the  package  in  a  cool 
oellar,  or  ice-house  or  well.  No  moisture  can  reach  them,  although 
the  package  is  placed  beneath  the  surface  of  water  in  the  well,  or 
sunk  to  the  bottom  thereof.  Moreover,  they  will  be  dried  more  thor- 
oughly when  deeply  imbedded  in  water,  for  manifest  reasons,  and  not 
only  protected  from  insects,  but  the  peculiar  animal,  which  forms  at 
their  expense,  (invariably  when  they  are  otherwise  stored  away,)  and 
equals  them  in  size  ultimately,  will  not  occur.  In  1868,  I  preserved 
them  thus  successfully,  in  my  cellar,  from  the  spring  until  autumn,  by 
attaching  a  slice  of  cork  to  a  thread,  which  facilitates  its  removal 
from  a  tube  vial  or  test-tube,"  when  forced  down  and  confined  by 
its  own  elasticity  to  the  lower  extremity ;  this  slice  of  cork  I  marked 
