AmjJuOne;i90^arm'}  NltrOgCIl    ill    GlllHS.  2$J 
into  a  small  quantity  of  water.  At  the  end  of  the  reaction  the  first 
flask  contained  a  small  quantity  of  colorless,  strongly  alkaline 
liquid,  sparingly  soluble  in  water,  but  readily  soluble  in  alcohol  and 
ether.    The  solution  was  tested  with  the  following  results: 
On  warming  with  hydrochloric  acid  and  allowing  to  stand  a  short 
time  a  fine  red  precipitate  separated.  With  sulphuric  acid  and 
quinone  a  green  precipitate  formed ;  with  phosphomolydic  acid, 
first  a  yellow,  then  a  blue  precipitate ;  with  potassium  ferrocyanide, 
dark  green  ;  with  quinone  alone,  violet  red.  The  contents  of  the 
second  flask  was  also  alkaline. 
This  proves  conclusively  that  the  gum  contained  nitrogen  in 
some  form,  which  is  converted  into  pyrrol,  or  a  pyrrol  derivative, 
by  heating  with  potassium  hydroxide. 
ATTEMPTS  TO  SEPARATE  THE  GUM  FROM  THE  ENZYME. 
Hikorokuro  Yoshida  states  that  by  removing  his  so-called  uru- 
shic  acid  with  alcohol  and  extracting  the  residue  with  cold  water, 
and  then  boiling  the  solution,  a  white  precipitate  is  formed.  He  as- 
sumes that  it  is  the  enzyme,  but  does  not  prove  it,  except  that  the 
solution  was  active  before  boiling  and  inactive  after  boiling,  and  that 
the  precipitate  contained  nitrogen.  It  may  have  been  an  inactive 
vegetable  albumen,  although  he  states  that  it  contained  less  nitro- 
gen than  these  bodies  usually  contain.  I  have  found,  however,  that 
a  solution  of  the  purified  gum  obtained  by  repeated  precipitation 
with  alcohol  remained  perfectly  clear  on  boiling;  yet,  previous  to 
boiling,  the  same  solution  was  strongly  active,  rapidly  changing 
tincture  of  guaiac  to  dark  blue,  and  the  clear  brown  resin  from  the 
lac  to  a  hard,  black  insoluble  substance. 
Solutions  of  the  gum  were  treated  with  acetic,  hydrochloric,  nitric 
and  sulphuric  acids  of  various  strengths  and  with  varying  degrees  of 
heat,  but  each  failed  to  separate  the  nitrogenous  substance  from  the 
gum.  In  one  experiment  the  solution  was  boiled  for  half  an  hour 
with  a  dilute  sulphuric  acid,  precipitated  with  alcohol,  dissolved  in 
water  and  reprecipitated  with  alcohol,  washed  until  free  from  sul- 
phuric acid,  and  dried  in  an  exsiccator.  This  still  gave  the  pyrrol 
reaction.  Fractional  precipitation  was  tried  without  apparent  change 
in  the  relation  of  gum  to  nitrogen.  Cold  saturated  solutions  of  mag- 
nesium sulphate,  ammonium  sulphate  and  sodium  phosphate  were  tried 
in  vain.  Various  modifications  of  Almen's  solution  of  tannic  acid  were 
tried,  but  in  no  case  was  there  any  separation  of  nitrogenous  from  non- 
