Ay0veXrP?9ai3m*}       Distribution  of  Tannin  Plants.  523 
frequently  its  greatest  use  is  in  countries  where  it  does  not  naturally 
occur.  In  many  cases  it  is  equally  unsafe  to  judge  of  the  botanical 
distribution  of  these  plants  from  the  localities  given  as  the  source  of 
the  material  used  in  the  analyses  reported  in  the  literature  of  the 
tannins.  The  writer  recently  examined  what  purported  to  be  a  list 
of  the  most  important  tannin  plants  of  the  world  in  which  the 
country  where  each  species  occurred  was  given.  On  tabulating  this 
list  the  following  distribution  of  the  species  was  obtained  : 
India   68  species 
Europe   40  species 
Australia   22  species 
North  America   16  species 
Africa   9  species 
Central  America  ....  7  species 
China    3  species 
lapan   3  species 
Chili   3  species 
Brazil  .   3  species 
Argentine    3  species 
New  Zealand   3  species 
Peru  .......   2  species 
Guiana    2  species 
Asia   2  species 
Mexico   1  species 
A  number  of  reasons  migjit.be  given  for  the  apparent  inequality 
in  distribution  shown  by  this  compilation,  but  it  will  suffice  to  say 
that  botanical  exploration,  particularly  with  respect  to  economic 
plants,  has  been  carried  much  further  in  India  and  Australia  than 
in  other  tropical  countries,  and  that  when  these  countries  shall  have 
been  fully  explored  substantial  additions  will  probably  be  made  to 
their  lists  of  tannin  plants.  In  this  connection  mention  may  be 
made  of  a  note  by  the  writer  in  the  Journal  of  this  Association  4 
in  which  attention  is  called  to  thirty-five  species  of  tannin  plants  in 
Paraguay,  only  one  of  which  is  referred  to  Paraguay  in  most  of  the 
literature  on  tannins. 
The  present  state  of  knowledge  with  respect  to  the  distribution 
of  tannin  plants  leaves  much  to  be  desired.  The  lack  of  information 
is  not  confined  to  the  conditions  in  the  less  accessible  tropical  coun- 
tries alone,  but  is  evident  also  wherever  it  becomes  desirable  to 
secure  full  details  concerning  the  production,  handling  and  utilization 
of  any  tannin  plant.  In  the  judgment  of  the  writer  there  is  less  need 
for  concern  regarding  the  possible  exhaustion  of  the  natural  supply 
of  tanning  materials  than  for  a  practical  solution  of  the  problem  of 
how  to  bring  them  into  the  market  on  terms  that  do  not  work  a 
hardship  either  to  producer  or  to  consumer.    So  long  as  these  mate- 
4  Stockberger,  W.  W.,  Tannin  Plants  of  Paragmy,  Journal  of  the  Ameri- 
can Leather  Chemists  Association,  April  1912.  p.  185-192. 
