Am.  Jour.  Pharm. 
July,  1900. 
Investigation  of  the  Tannins. 
339 
Ash  in  Tannin  in 
Absolutely  Dry      Absolutely  Dry 
Species.  Part.  Moisture.      Material.  Material. 
R.  semialata         Leaves  5*98  7*26  277 
R.  semialata  Root  bark    ....   6*23  12*00  7*40 
R.  canadensis        Leaves  10*55  7*75  21*62 
The  leaves  of  the  R.  canadensis  were  collected  in  Tennessee  in 
August,  1894.    The  purified  tannin  of  the  leaves  showed: 
Per  Cent. 
Carbon  5281 
Hydrogen    3*17 
•  Oxygen   44*02 
It  was  noticed  during  the  work  on  the  lines  of  these  several  species 
of  sumach  that  malic  acid  and  acid  malates  interfere  in  the  hide- 
powder  process  of  estimating  tannin  by  being  taken  up  by  the  hide, 
thus  immersing  the  figure  for  tannin.  Neutral  malates  are  not  so 
absorbed,  and  were  found  to  cause  no  interference  in  this  manner. 
Tannin  of  Ron  Ron. — This  material  was  procured  from  the  Com- 
mercial Museum  of  Philadelphia.  It  is  said  to  be  the  wood  of  a 
member  of  the  Anacardiacese,  which  grows  in  Costa  Rica. 
The  wood  contained  6*87  per  cent,  of  moisture,  and  upon  ignition 
left  an  ash  containing  potassium  and  calcium  carbonates  and  phos- 
phates. The  ash  amounted  to  1*58  per  cent,  of  the  thoroughly 
dried  wood.  The  tannin  of  Ron  Ron  gave  a  yellow  precipitate 
with  bromine  water,  and  a  dark  green  precipitate  with  ferric  alum. 
These  characters  ally  it  to  the  members  of  the  oak  bark  tannin 
group.  The  air-dry  wood  contained  6*32  per  cent,  of  tannin,  which 
calculated  for  the  absolutely  dry  wood  equals  6*78  per  cent. 
CONIFERS. 
Chamcecyparis  Spheroidea. — A  sample  of  the  bark  of  the  white 
cedar,  Chamaecyparis  spheroidea,  was  estimated,  with  the  following 
result : 
Per  Cent. 
Moisture  34*75 
Ash  in  absolutely  dry  bark  2*88 
Tannin  in  absolutely  dry  bark  4*44 
The  sample  was  collected  near  Haddonfield,  N.  J.,  on  June  21  f 
1894. 
Taxodium  Distichum. — A  sample  of  the  bark  of  Taxodium  dis- 
tichum  was  collected  on  June  28,  1895,  at  the  Painter  Arboretum, 
