Am.  Jour.  Pharni. ") 
May,  1884.  J 
Sorghum  Sugar. 
259 
of  sugar,  passes  to  the  evaporating  pans,  where  it  is  boiled  down  to 
54  parts  of  water  and  46  parts  of  sugar,  when  it  is  called  "  semi- 
syrup."  This  passes  into  a  small  vacuum  pan,  and  from  there  into  the 
bone-black  filters.  These  are  six  in  number,  and  are  each  cylindrical 
in  shape,  four  feet  in  diameter  and  20  feet  high.  Here  the  syrup  is 
decolorized  and  deodorized,  after  which  it  is  pumped  into  the  large 
vacuum  pan.  This  is  ovoid  in  shape,  made  of  boiler  iron,  and  looks 
like  a  huge  retort.  It  is  seven  feet  in  diameter,  nine  feet  high,  and 
will  hold  more  than  1,000  gallons.  In  this  the  semi-syrup  boils  at 
70°  C.  under  diminished  pressure,  instead  of  110°  C.  in  free  air.  This 
is  a  great  advantage,  as  it  is  a  well-established  fact  that  high  heat  and 
much  exposure  to  the  air  quickens  the  conversion  of  sacharose  into 
invert  sugar.  From  the  vacuum  pan  the  syrup  is  put  into  large  iron 
wagons,  which  hold  about  250  gallons  each,  and  in  them  is  run  into 
the  crystallizing  room.  This  room  is  kept  at  a  temperature  of  55°  C, 
and  in  it  the  syrup  is  allowed  to  stand  for  several  days  until  it  crystal- 
lizes. The  "  melado/'  as  the  syrup  at  this  stage  is  called,  is  then  run 
into  the  mixer.  This  is  a  long  bar  with  fingers  attached,  the  whole 
revolving  in  an  iron  box.  In  this  the  melado  is  thoroughly  mixed 
and  made  ready  for  the  last  process.  From  the  mixer  the  melado  is 
run  into  the  centrifugals.  These,  four  in  number,  are  tubular  vessels 
about  three  feet  in  length  and  two  feet  high,  open  above  and  closed 
below.  Each  is  lined  with  fine  copper  sieve,  a  space  of  perhaps  two 
or  three  inches  intervening  between  the  sieve  and  the  outer  wall  of  the 
centrifugal.  The  centrifugals  are  set  in  motion  at  the  rate  of  2,000 
revolutions  per  minute,  and  the  melado  is  run  into  them,  falling  upon 
a  revolving  disk  in  the  centre.  From  this  the  melado  is  thrown  with 
great  force  against  the  side  of  the  vessel,  striking  upon  the  copper 
sieve,  which  is  also  in  rapid  revolution.  The  force  of  the  projection 
throws  the  syrup  through  the  sieve,  while  the  crystallized  sugar  remains 
behind,  whitening  the  longer  it  "  spins,"  as  the  process  is  called.  It 
is  generally  allowed  to  spin  about  fifteen  minutes,  after  which  the  raw 
sugar  is  taken  out  and  put  into  barrels,  and  the  process  is  completed. 
Each  centrifugal  is  capable  of  spinning  200  lbs.  of  sugar  in  those 
fifteen  minutes.  Besides  these  details,  the  process  has,  of  course,  its 
secrets,  which  are  also  kept  as  such. 
From  the  above-named  factory  I  obtained  a  sample  of  sugar,  of 
which  I  made  an  analysis,  which  shortly  will  be  explained.  In  appear- 
ance the  sugar  looks  very  much  like  the  common  raw  sugar  of  com- 
