124 
Dioscorea  Batatas. 
(  Am.  Jour.  Pharm. 
1      March,  1893. 
The  original  drug  was  then  dried,  to  remove  alcohol,  and 
extracted  with  500  cc.  of  water,  in  two  portions,  each  macerating 
for  24  hours.  Fifty  cubic  centimetres  of  this  aqueous  extract  were 
evaporated  to  dryness,  weighed  and  then  ignited,  so  as  to  obtain 
the  amount  of  organic  matter  it  contained  in  solution.  To  25  cc. 
of  the  aqueous  extract,  75  cc.  of  absolute  alcohol  were  added  ;  the 
precipitated  mucilage  was  collected,  washed,  and  dried  at  ioo°  C, 
and  then  weighed. 
The  filtrate  was  evaporated  to  a  syrupy  consistency,  on  a  water 
bath,  and  to  this  25  cc.  of  absolute  alcohol  were  added,  and  the 
dextrin  was  precipitated,  washed,  dried  and  weighed. 
Another  25  cc.  of  the  aqueous  extract  were  precipitated  by 
plumbic  acetate,  the  filtrate  freed  from  lead  by  hydrogen  sulphide, 
then  divided  into  two  equal  parts,  of  which  one  was  used  for  the 
estimation  of  glucose  present,  and  the  other  part  for  the  estimation 
of  saccharose  by  inversion  with  hydrochloric  acid  and  treatment 
with  Fehling's  solution. 
The  drug  was  next  extracted  with  500  cc.  of  sodium  hydrate 
solution,  in  two  portions.  Fifty  cubic  centimetres  of  this  alkaline 
liquid  were  evaporated  to  dryness,  weighed  and  then  ignited  to 
obtain  the  amount  of  organic  matter.  Then  25  cc.  of  the  alkaline 
liquid  were  made  acid  with  acetic  acid,  and  to  this  75  cc.  of  95  per 
cent,  alcohol  were  added,  so  as  to  precipitate  the  albumen  and 
pectin. 
By  exhausting  the  drug  with  acidulated  water,  a  liquid  was 
obtained  in  which  the  total  organic  matter  was  determined,  also 
calcium  oxalate  and  pararabin. 
On  boiling  the  drug  with  water,  the  starch  was  extracted,  and 
after  determining  the  total  amount  of  organic  matter,  the  liquid  was 
boiled  with  sulphuric  acid,  and  the  starch  subsequently  estimated 
as  glucose. 
The  residual  drug  was  dried,  weighed,  and  after  treatment  with 
fresh  chlorine  water,  to  dissolve  the  lignin,was  again  dried,  weighed 
and  a  portion  ignited  to  obtain  the  amount  of  cellulin. 
A  weighed  quantity  of  fresh  drug  was  dried  at  uo°  C,  in  an 
air  bath,  to  constant  weight,  and  the  amount  of  moisture  the 
drug  contained  was  then  estimated.  The  residue  was  ignited  and 
weighed,  which  gave  the  amount  of  ash  the  drug  contained. 
One  hundred  grams  of  the  drug  were  all  that  could  be  gotten, 
