Correspondence. 
f  Am.  Jour.  Pharm. 
\       April,  1910. 
lowing  suggestions  which  have  come  from  my  personal  experience. 
I.  Too  little  attention  is  paid  in  the  average  percolation  to 
loss  of  menstruum,  both  by  evaporation  and  through  absorption  of 
the  marc. 
II.  Loss  by  evaporation  can  be  prevented  by  suitable  apparatus 
similar  to  that  used  ordinarily  in  percolation  of  volatile  liquids 
(see  "Economic  Percolation."  Proc.  A.  Ph.  A..  1892,  p.  169). 
III.  To  make  percolation  profitable,  the  alcohol  in  the  moist 
marc  should  be  recovered.  As  to  the  two  methods,  that  of  per- 
colating the  marc  with  water  and  collecting  the  percolate  ap- 
proximating the  amount  of  menstruum  with  which  the  marc  was 
wet  has  never  appealed  to  me.  Far  better  is  distilling  the  mar: 
with  steam,  nor  is  this  process  one  which  should  frighten  the 
retailer.  In  my  own  retail  experience  I  used  a  steam  distilling 
apparatus  consisting  of  a  boiler  made  from  a  one-gallon  tin  can, 
provided  with  a  cork  with  two  holes,  through  one  of  which  passed 
a  straight  safety  tube,  through  the  other  a  bent  tube  to  convey 
the  steam,  which  passed  into  the  distilling  jar  which  consisted  of 
a  wide-mouthed  half  gallon  candy  jar.  I  kept  a  half  dozen  such 
candy  jars  on  hand  for  this  purpose  and  the  moist  marc  from 
every  percolation  (even  though  only  an  ounce)  was  transferred  to 
the  jar.  which  of  course  was  kept  tightly  corked.  The  jars  were 
only  half  filled  with  marc  and  when  the  six  jars  were  thus  half 
filled,  the  distilling  apparatus  was  rigged  up  and  the  alcohol  from 
the  10-12  pounds  of  marc  was  easilv  condensed,  the  jar  being 
removed  from  the  current  of  steam  when  the  distillate  was  no 
longer  alcoholic  and  replaced  by  another  one  containing  undistilled 
marc.  Since  teaching,  I  have  found  it  difficult  to  secure  corks 
suitable  for  the  candy  jars,  and  have  had  made  at  the  local  can 
factory  1 -gallon  tin  cans  with  larger  mouths  than  ordinary — a> 
large  as  will  fit  the  largest  corks  now  obtainable.  These  are  in 
some  respects  not  as  satisfactory  as  the  jars  which  in  our  drug 
business  were  so  abundant  that  the  occasional  breaking  of  one 
meant  no  real  loss.  Of  course  the  steam  distilling  apparatus  must 
include  a  condenser,  a  fact  so  self-evident  that  I  mention  it  merely 
for  the  sake  of  completeness. 
IV.  There  is  a  lack  of  appreciation  of  the  very  great  import- 
ance of  careful  percolation.  Given  the  same  drug  and  the  same 
menstruum  despite  careful  warnings  as  to  speed  of  percolation, 
twenty  operators  will  obtain  as  "  first  percolates  "  fluids  of  almost 
