km.  Jour.  Pharm.  \ 
December.  1906.  i 
United  States  Army  Laboratory. 
571 
often  two  inches  deep,  remained  on  the  surface  of  the  acid  liquid 
residue  in  the  retort.  If  by  any  chance  this  solid  crust  was  rup- 
tured during  the  distillation,  or  if  it  failed  to  form,  the  contents  of 
the  retort  invariably  frothed  over  at  some  period  during  the  8  or  10 
hours  which,  on  an  average,  were  consumed  in  the  distillation. 
The  furnace  in  the  rear  of  the  stack  enclosed  a  large  kettle  (F) 
which  was  used  mainly  for  preparing  solutions  of  saline  compounds 
of  various  descriptions,  such  as  liquor  potassae,  the  carbonates  of 
soda  and  potash,  etc.,  which  in  turn  were  used  for  a  variety  of  pur- 
poses ;  the  sodium  carbonate  for  making 
Solution  of  Chlorinated  Sada,  by  admixture  with  solution  of 
chlorinated  lime  in  the  huge  tank  or  tub,  capable  of  holding  several 
hundred  gallons,  indicated  by  (O)  in  the  northeast  corner  of  the 
room,  while  the 
Potassium  Carbonate  was  purified  by  filtering  the  solution  and 
evaporating  it  to  dryness  in  shallow  vessels  on  one  of  the  furnace 
openings  indicated  by  (G)  on  the  western  side  of  the  stack.  These 
openings  were  also  provided  with  sand  baths,  on  which,  in  shallow 
porcelain  lined  vessels,  solution  of 
Potassium  Acetate,  previously  prepared  in  stone- ware  jars,  was 
evaporated  to  dryness,  and  then,  while  still  hot,  filled  into  wide- 
mouthed,  well-dried  bottles,  and  immediately  corked.  A  number 
of  large  wooden  tubs,  of  100  gallon  capacity,  indicated  by  (n,  n,  n,) 
were  used  mainly  for  the  purpose  of  precipitating  ferric  hydroxide, 
this  in  turn  being  used  for  making 
Citrate  of  Iron,  most  of  this  being  converted  into 
Citrate  of  Iron  and  Quinine,  of  which  immense  quantities  were  in 
constant  requisition.  These  solutions,  after  proper  concentration, 
were  transferred  in  earthen-ware  jars  to  the  scaling  room,  situated 
on  the  third  floor  of  the  main  building,  where  a  man  was  continu- 
ously employed  in  painting  them  on  the  surface  of  panes  of  glass, 
from  which,  after  drying  in  a  hot  closet,  they  were  removed  in  form 
of  scales  by  simply  tapping  the  glass  edgewise  on  the  surface  of  the 
work  table,  aided,  under  unfavorable  conditions,  by  scraping  with  a 
spatula.  The 
Solution  of  Ferric  Sulphate  required  for  precipating  the  ferric 
hydroxide  was  prepared  in  large  enameled  kettles  on  the  furnace 
under  a  shed  on  the  outside  of  the  building,  indicated  by  (AT),  this 
obviating  the  necessity  of  a  fume  chamber  during  the  process  of 
