156  Literature  Relating  to  Pharmacy.  {A™it™h:w7&rm* 
pared.  A  second  acid,  present  to  the  extent  of  about  4  per  cent, 
only,  was  also  obtained;  to  this  the  name  isotrachylolic  acid  was 
assigned.  These  two  acids,  together  with  about  6  per  cent,  of 
a-copal  resin  and  /9-copal  resin,  a  bitter  principle  and  volatile  oil, 
form  the  constituents  of  Zanzibar  copal  as  far  as  the  author  could 
succeed  in  separating  them. 
An  examination  of  the  stems  sent  from  Usegna  showed  that, 
although  the  primary  cortex  contains  schizogenous  secretion  ducts, 
these  are  soon  thrown  off  as  the  secondary  cortex  is  produced,  and 
in  the  bark  of  older  twigs  and  of  the  stem  no  ducts  could  be  found. 
The  resin  appears,  therefore,  to  the  author  to  be  a  pathological 
product. 
RECENT  LITERATURE  RELATING  TO  PHARMACY. 
ASSAY  OF  JOHORE  GAMBIER. 
W.  O.  Richtmann  {Pharmaceutical  Review,  15,  27)  has  examined 
six  specimens  of  Johore  gambier  obtained  by  the  University  or 
Wisconsin  from  the  Columbian  Exposition.  The  tannin  was  esti 
mated  by  the  process  recommended  by  the  Commission  of  German 
Technical  Chemists  and  published  in  1885;  the  catechin  was  deter- 
mined by  extracting  it  from  the  aqueous  solution  of  the  gambier, 
and  the  ash  and  moisture  according  to  the  usual  methods.  The 
following  are  the  results  in  per  cent. : 
Specimen  No.  Moisture.  Ash.  Tannin.  Catechin. 
2,900   12-37  4-35  39-63  iric 
2,901   II-20  3-63  32*51  9'22 
2,902   1-38  3-65  40-51  9*39 
2.904   1-50  1-87  46-95  5'25 
2.905   8-37  3-77  22-21  8-68 
2.906   7*oo  4*13  29*94  6-98 
The  presence  of  two  fungi,  Penicillium  glaucum  and  Aspergillus 
niger,  was  demonstrated. 
ON  THE  SEPARATION  OF  NITRATE  OF  COPPER  FROM  NITRATE  OF 
SILVER  IN  THE  MANUFACTURE  OF  CAUSTIC. 
C.  J.  H.  Warden  {Pharmaceutical  Journal,  January  23,  1897)  gives 
the  following  method  for  separating  these  two  salts  :  It  is  not  gen- 
erally known  that  strong  nitric  acid  precipitates  nitrate  of  silver 
from  concentrated  aqueous  solutions,  and  this  action  has  been  used 
