Am.  Jour.  Pharm.  \ 
November,  1907.  / 
Poison  Sumac. 
extent  of  such  variations.  The  specific  gravity  would  probably  vary 
also,  but  no  experiments  were  made  to  verify  this  supposition. 
Date  of  Collection. 
Soluble  in 
Alcohol. 
Insoluble  in 
Insoluble  in  Alcohol. 
Water 
"  Crude 
Resin." 
Alcohol. 
Soluble  in 
Water. 
Insoluble  in 
Water. 
(by  difference). 
October  20,  1905    .  .  . 
So' 458 
6-134 
4*393 
i'74i 
13-408 
June  1,  1906  ..... 
79-608 
5'3l6 
3*371 
1*945 
15-076 
August  29,  1906  .... 
75'892 
5*175 
3*476 
1-699 
i8-933 
October  20,  1906    .  .  . 
From  near  toot  of 
trees,  Nov.  3,  1906 
84*330 
80-223 
5*°99 
8*018 
3*994 
5*393 
1*705 
2-625 
9-971 
n'759 
For  comparison  we  append  a  tabular  statement  of  the  composition 
of  Japanese  lac  compiled  from  the  reports  of  various  workers. 
Observer. 
Soluble  in 
Alcohol. 
"  Urushic 
Acid." 
Insoluble  in 
Alcohol. 
Calculated  by 
Stevens  and 
Warren. 
Gum. 
Nitrogenous 
Residue. 
Water  and 
Volatile  Matter 
(by  difference). 
Ishimatsu  
58*24 
8*59 
6-32 
227 
33*17 
85*15 
5*43 
3*i5 
2-28 
9-42 
Korshelt  and  Yoshida 
80  "oo 
8  00 
4-69 
3*3i 
1200 
Insoluble  in  Alcohol. 
Soluble  in 
Water. 
Insoluble  in 
Water. 
Tschirch  and  Stevens 
72-40 
6-40 
4*05 
2*35 
21*20 
RESIDUE  INSOLUBLE  IN  ALCOHOL. 
The  alcoholic-insoluble  residue  was  dissolved  in  cold  water  as 
completely  as  possible  (by  trituration  in  a  mortar  with  a  small  quan- 
tity of  water)  and  filtered  into  a  small  quantity  of  alcohol.  The 
resulting  mixture  was  then  poured  into  a  large  volume  of  alcohol. 
A  white  precipitate  was  produced  which,  after  purification  by  repeat- 
ing the  above  process  several  times,  was  found  to  have  the  proper- 
ties of  the  gum  obtained  by  Ishimatsu,25  Stevens26  and  others  from 
Japanese  lac.  In  most  respects  it  was  similar  to  gum  acacia  under 
the  same  conditions.  When  prepared  as  described  above,  after  fil- 
tering and  drying,  this  gum  possesses  a  powerful  enzymatic  action 
Manchester  Lit.  and  Philos.  Soc.  [3],  249.  1S82. 
"  Japanese  Lac."    Dissertation.    A.  B.  Stevens,  43.  1906. 
