Am.  Jour.  Pharro. ) 
December,  1906.  / 
United  States  Army  Laboratory. 
567 
loss.  From  time  to  time  the  sodium  sulphate  accumulating  in  the 
subliming  tube  was  scraped  out  with  the  feeding  spoon.  The  novel 
idea  of  carrying  the  sublimate  vapor  into  a  chamber  and  condensing 
it  in  fine  powder  form,  instead  of  subliming  it  in  crystalline  masses, 
as  is  and  has  been  the  practice  of  manufacturers,  was  conceived  by 
Professor  Maisch  in  consequence  of  the  demand  of  the  Medical  Pur- 
veyor for  large  quantities  of  powdered  corrosive  sublimate  and  the 
danger  incurred  by  the  operator  during  the  ordinary  process  of  reduc- 
ing the  crystalline  salt  to  powder.  The  one  doubt  that  presented  itsell 
to  our  minds  was  the  failure  of  a  sufficient  draught  to  prevent  the 
Fig.  5. — Subliming  Chamber  for  Corrosive  Sublimate. 
leakage  of  the  vapor  through  the  joints  formed  by  the  sliding  doors 
of  the  chamber,  well  shown  in  the  half-tone  picture  (Fig.  5),  on  the 
one  hand,  or  the  possible  loss  by  excess  of  draught,  which  might 
carry  much  of  the  mercurial  vapor  into  the  chimney,  on  the 
other.  But  both  of  these  points  were  definitely  and  favorably  settled 
after  the  first  few  trials.  The  draught  being  inward,  no  corrosive  sub- 
limate vapor  escaped  into  the  laboratory  ;  and  the  distance  traversed 
by  the  vapor  insured  its  practically  complete  condensation  before 
it  reached  the  exit  into  the  flue.  It  is  safe  to  say,  that  this  idea  has 
given  the  incentive  to  other  applications  of  a  principle  which  had 
previous  to  this  time  been  applied  probably  only  to  the  sublimation 
