Ana.  Jour.  Pharrn.  \ 
February.  1906.  J 
Japanese  Lac. 
59 
precipitate,  and  assumes  that  it  is  the  enzyme  that  has  been  re- 
moved ;  but  such  cannot  be  the  case,  as  a  solution  of  the  pure  gum, 
which  is  very  active,  does  not  give  any  precipitate  on  boiling.  The 
precipitate  may  have  been  some  vegetable  albumen  which  was  pres- 
ent in  the  lac,  but  I  have  been  unable  to  find  it  after  repeated  trials. 
All  attempts  to  free  the  gum  from  nitrogen  have  been  without  suc- 
cess. 
Oxidation  Products  of  Gum-enzyme. — Mucic  acid  is  the  principal 
product  obtained  by  oxidizing  the  gum-enzyme  with  nitric  acid 
1*150  sp.  gr.    Oxalic  acid  and  tartaric  acids  were  also  formed. 
Hydrolysis  of  Gum-enzyme. — The  gum-enzyme  was  heated  for 
eight  hours  with  2  per  cent,  sulphuric  acid,  and  the  acid  removed 
with  barium  hydroxide  and  carbonate.  The  solution  was  evapo- 
rated under  diminished  pressure,  when  it  formed  a  light  yellow 
syrup,  noncrystallizable,  nonfermentable,  reduced  Fehling's  solution 
and  was  dextrorotary. 
One  part  of  the  syrup  was  heated  one  hour  with  2  parts  of  phe- 
nylhydrazine,  3  parts  of  sodium  acetate,  and  20  parts  of  water.  On 
cooling,  an  abundant  yellow  crystalline  deposit  formed.  This  was 
several  times  recrystallized  from  hot  alcohol  when  the  melting 
point  remained  constant,  beginning  at  1620  C.  and  was  complete  at 
1640  C.  without  the  liberation  of  gas.  The  crystals  were  in  small 
spheroidal  clusters,  which  under  the  microscope  appeared  to  consist 
of  aggregations  of  needles.  This  corresponds  exactly  with  the 
description  and  melting  point  given  for  phenylsorbinazone.1  A 
second  crop  of  crystals  was  obtained  by  concentrating  the  mother 
liquor.  These  were  somewhat  darker  than  the  first,  and  had  a  melt- 
ing point  of  1 570  C.,  but  with  the  production  of  gas.  This  corre- 
sponds with  the  description  given  for  inactive  sorbinazone. 
Bertrand,2  when  working  with  soluble  oxiding  ferments,  used  the 
gum-enzyme  from  Japanese  lac  under  the  name  "  Laccasse."  He 
reports  that  it  contained  0  44  per  cent,  of  nitrogen,  which  he  deter- 
mined by  heating  with  soda-lime  and  estimating  the  ammonia 
formed  by  titrating  with  decinormal  sulphuric  acid.  From  this  he 
calculated  the  amount  of  enzyme  present  by  assuming  that  it  has 
the  elementary  composition  of  albumenous  substances.  He  then 
gives  the  composition  of  the  gum-enzyme  as : 
1  Vaubel,  Quantitative  Bestimmung.  Organ.  Verbiudungen,  II  Baud,  3,  304. 
2  Bull.  Soc.  Chem.,  third  series,  51,  p.  259,  1891. 
