376 
Sorgho  and  Imphy-Sugar. 
?  Am.  Jour.  Pharm. 
1     July,  1883., 
Oane-sugar. 
Glucose. 
1. 
0-23—  4-91 
3-32— 6-37 
2. 
2'89—  6-54 
3-26— 5-26 
3. 
7-84— n- 78 
2-16— 6-04 
4. 
9-24— 13-57 
1-19— 4-05 
An  analysis  of  sorgho  juice  gave — water^ 
80  per  cent. 
;  cane-sugar  J 
15-17  per  cent.;  glucose,  1  per  cent.;  starch,  gum,  pectic  acid, 
albumin,  red  coloring  matter,  ash,  etc.,  undetermined.  The  most 
primitive  method  of  defecating  the  juice  consists  in  heating  it  to 
70-80°  and  adding  lime ;  at  this  temperature,  the  starch  swells  and 
diffuses  throughout  the  liquid,  and  subsequently  prevents  the  evapora- 
tion being  carried  to  tlie  point  necessary  for  the  crystallization  of  the 
cane-sugar.  A  better  method  is  to  carefully  filter  the  juice  through  a 
series  of  filters  to  remove  impurities  which  promote  fermentation, 
hinder  evaporation,  and  impart  a  color  to  the  product.  After  filtra- 
tion the  juice  is  mixed  with  lime,  and  allowed  to  stand  at  the  ordinary 
temperature  for  a  certain  time ;  the  clear  liquid  is  then  evaporated. 
A  still  more  complex  method  proposed  is  to  mix  the  juice  from  the 
mill  with  lime,  magnesia,  and  its  own  volume  of  alcohol  of  84  per 
cent.;  to  decant  the  clear  liquor  after  settling,  and  to  press  the  residue 
into  cakes  for  feeding,  or  for  the  production  of  alcohol ;  to  distil  the 
alcohol  off  from  the  purified  solution,  and  continue  the  evaporation  of 
the  latter  to  the  crystallizing  point.  F.  Stewart's  process  of 
defecation  proceeds  by  heating  the  juice  to  82°  with  lime  in  copper 
vessels,  filtering,  and  evaporating  with  the  addition  of  an  acid  liquid, 
the  composition  of  which  is  not  published.  The  evaporation  of  the 
defecated  liquid  is  conducted  in  a  very  primitive  fashion  in  the 
States.  Four  kettles  of  diminishing  size  are  used,  each  being  divided 
into  several  compartments  to  moderate  the  ebullition ;  the  syrup  is 
transferred  from  one  kettle  to  another  by  a  long-handled  bowl, 
skimmed  from  time  to  time,  and  when  sufficiently  concentrated  filtered 
through  canvas. 
The  refining  is  conducted  in  a  simple  cylindrical  vessel,  packed  with 
animal  charcoal  and  sand  or  gravel.  The  only  analysis  of  sorgho 
sugar  known  to  the  author  gave — water,  1*72;  cane-sugar,  93*05; 
glucose,  0*41;  ash,  0*68;  organic  matter,  4'14. — Jour.  Chem.  Soc, 
1883,  p.  633;  Ann.  Agron.,  1882,  146;  D.  Industrie  Ztg. 
