558 
Chemistry  of  Bast  Fibres, 
(  Am.  [our.  Ptiarm. 
\     'Nov.,  1880. 
(b.)  Jsh. — ^^The  general  features  of  the  inorganic  skeleton  of  this 
fibre  may  be  expressed  by  the  following  average  percentage  numbers  : 
SiOg,  30—35  ;  Fe203,  5—8  ;  AI2O3,  5—6  ;  Mn203,  0*5— 0  9  ;  CaO, 
13—16  ;  K^O-fNa^O,  5-10  ;  P^O^,  8—13  ;  SO3,  1—5. 
(c.)  Organic  (considered  with  exclusion  of  a  and  b). — Combustions 
of  the  fibre  (purified  by  boiling  in  dilute  ammonia  \  the  fibre  thereby 
sustains  a  loss  of  i  per  cent,  of  its  weight,  losing  a  resinous  constituent, 
which  causes  the  adhesion  of  portions  of  cortical  parenchyma  and  the 
matting  together  of  the  fibres  in  the  raw  state),  showed  it  to  have  the 
following  aggregate  (average)  composition:  0,46*5;  H,  5*80  Nitro- 
gen is  present  only  in  minute  quantity,  e.g.^  in  a  fair  specimen  (previ- 
ously boiled  in  dilute  sodium  carbonate)  the  quantity  determined  was 
0*053  per  cent.  The  proximate  constituents  of  the  fibre  are,  cellulose^ 
70  per  cent.,  as  isolated  by  the  ordinary  methods,  and  intercellular  and 
.encrusting  substance^  30  per  cent. 
Hugo  Muller's  method  for  the  quantitative  determination  of  cellulose 
gives  satisfactory  results  with  this  fibre  ;  identical  results  are  obtained, 
but  in  a  very  much  shorter  time  by  substituting  chlorine  gas  for  the 
bromine-water,  the  fibre  being  boiled  previously  to  chlorination  in  a 
weak  alkalme  solution.  The  action  of  the  gas  is  to  form  a  definite 
compound  with  the  aromatic  portion  of  the  fibre,  which  is  decomposed 
on  boiling  with  ammonia,  with  formation  of  soluble  products.  Pure 
cellulose  is  obtained  on  once  repeating  this  treatment,  whilst  if  bro- 
mine-water is  used  several  repetitions  (5  to  6)  are  necessary.  A.  modi- 
fication of  this  method,  involving  points  discussed  in  another  connection, 
consists  in  boiling  the  chlorinated  fibre  with  a  solution  of  sodium  sul- 
phite (5  per  cent.)  for  a  few  minutes,  and  subsequently  with  an  alkali 
(a  solution  of  potash,  i  per  cent.,  is  a  better  solvent  for  the  products 
of  decomposition,  and  its  use  does  not  affect  the  yield  of  cellulose); 
by  the  method  thus  modified  pure  cellulose  is  at  once  obtained.  It  is 
a  remarkable  fact  that  the  yield  of  cellulose  is,  in  this  case,  5  per  cent, 
higher  than  by  either  of  the  two  previous  methods.  There  is  addi- 
tional evidence  to  show  that  jute  cellulose  is  a  chemical  aggregate, 
and  therefore  to  a  certain  extent  defined  by  the  process  by  which  it  is 
obtained.  The  above-mentioned  chlorine  derivative  is  a  definite  com- 
pound, CjgHigCl^O^;  it  has  been  obtained  and  purified  in  different  ways, 
but  with  constant  analytical  results.  It  is  soluble  in  alcohol  and  glacial 
acetic  acid,  and  is  precipitated  from  its  solution  on  the  addition  of  water, 
in  yellow  flocks  ;   it  dries  to  an  amorphous  yellowish  powder,  which 
