ON  A  STILL  FOE  APOTHECARIES. 
15 
the  operator  extends  apiece  of  moist,  loose  .textured,  coarse 
twine,  around  the   centre   of  the  iron    flange,  crossing  the 
ends.    The  head  is  then  placed  in  position,  and  by  the  aid  of  five 
clamps,  see  fig.  2,  the  flanges  are  compressed  strongly  together, 
when  the  twine  forms  an  air-tight  joint;  of  course,  a  ring  of  rub- 
ber would  be  more  elegant,  but  scarcely  more  effective,  and  by  no 
means  so  convenient  and  economical.    This  simple  idea  I  owe  to 
a  recent  visit  to  the  laboratory  of  Dr.  E.  E.  Squibb,  who  gave  me 
permission  to  use  and  describe  it.    When  in  operation,  the  boiler 
should  be  supported  in  a  jacket,  as,  for  instance,  the  top  of  a 
common  cylindrical  stove,  by  means  of  a  ring  of  sheet  iron 
pressing   against  the  lower  side  of  the  clamps.    A  current 
of  cold  water  is  allowed  to  run  into  A,  which  carries  it  directly  to 
the  neck,  where  the  largest  amount  of  vapor  is  to  be  condensed, 
and  which  should  be  kept  cooler  than  any  other  part  of  the 
condensing  surface.    The  tubulure  at  /  enables  the  operator  to 
inspect  the  interior,  by  means  of  a  glass  or  wooden  rod.    A  gum 
tube  will  convey  the  waste  water  away  from  L    In  distilling 
very  volatile  liquids  a  Liebig's  or  other  condenser  may  be  at- 
tached to  the  neck,  at  m,  if  it  is  deemed  advisable.    Gas  heat 
is  admirably  adapted  for  this  still  when  used  with  a  jacket,  and 
when  the  distillation  of  alcoholic  solutions  is  carried  nearly  to 
dryness,  a  water  bath  jacket  may  be  employed.    Of  course,  in 
using  this  still  for  recovering  ether,  every  precaution  should  be 
taken  as  regards  tight  joints  and  effectual  condensation — using  a 
water  bath  heat,  and  ice  water  in  the  condenser,  the  neck  being 
luted  to  the  receiver,  which,  of  course,  should  be  ventilated  by 
a  small  opening  to  prevent  accidents.    The  tubulure,  in  this  case, 
should  be  well  closed  with  a  good  velvet  cork.    The  apparatus 
exhibited  cost  eleven  dollars,  but  this  great  price  arose  from  the 
clamps  and  tinned  flanges,  which,  were  the  apparatus  much 
used,  could  be  made  much  more  cheaply.    This  still  was  con- 
structed by  Mr.  Isaac  S.  Williams,  726  Market  street,  Philadel- 
phia.— Ptoc.  Amer.  Pharm.  Assoc.,  1863. 
Philadelphia,  Sept.  5th,  1863. 
