205 
of  the  balls  thus  affected,  in  search  of  some  sort  of  an  antiseptic, 
and  am  pleased  to  say  that  my  endeavors  have  produced  satisfactor\^ 
results.  At  this  stage  I should  acknowledge  that  my  experiments 
have  not  been  exhaustive,  since  I only  applied  my  tests  to  small 
quantities.  It  remains,  therefore,  to  be  seen  whether  or  not  the 
application  of  the  same  antiseptics  will  be  equally  efficacious  when 
applied  to  large  masses  of  the  affected  gum.  I am  afraid  not,  and 
in  all  that  concerns  the  healthful  preservation  of  the  gum  I incline 
to  the  maxim  that  it  is  better  to  prevent  an  evil  than  to  provide  a 
cure  for  it. 
Unfortunately  the  greatest  enemy  to  our  Congo  rubber  trade 
is  the  reputation,  fostered  by  others,  that  there  is  not  a pound  of 
absolutely  healthy  Congo  rubber  to  be  found  in  Annverp.  Equally 
unfortunate  is  the  fact  that  there  is  no  fixed  rule  whereby  the  de- 
generation or  depreciation  in  the  value  of  rubber  from  oxidation  may 
be  satisfactorily  computed.  I will  give  here  an  example  of  the 
difference  in  price  obtained  for  two  lots  of  the  same  consignment 
of  rubber  of  which  one  lot  was  perfectly  healthy  and  the  other  in 
poor  condition.  The  lots  were  of  about  five  tons  each.  The  first, 
which  we  shall  call  lot  A.,  was  sold  for  3.50  francs  per  kilo.  Of  the 
second  lot,  which  we  shall  call  lot  B..  two  tons  were  wholly  sound, 
and  three  tons  more  or  less  sticky  (about  the  normal  proportion). 
Lot  B.  sold  for  only  4.90  francs.  Compared  then  with  the  price 
obtained  for  lot  A.,  lot  B.  suffered  a discount  of  60  centimes  per 
kilo,  or  about  3,000  francs  (S600)  for  the  5 tons. 
From  this  case,  however,  we  must  not  augur  that  all  the  lots 
■containing  portions  more  or  less  viscous  suffered  a depreciation 
of  60  centimes  per  kilo,  upon  the  prices  paid  for  healthy  rubber. 
On  the  contrary,  the  discount  is  sometimes  more  and  sometimes 
even  less ; this  figure  is  by  no  means  fixed,  cmd  the  loss  depends  upon 
the  quantity  of  the  affected  gum  and  the  degree  of  the  oxidation. 
However,  when  we  consider  that  the  greater  part  of  the  lots 
emanating  from  the  Congo  region  are  more  or  less  tainted,  we  may 
easily  calculate  the  importance  of  the  loss  on  the  total  caoutchouc 
production  of  the  Congo. — The  India  Rubber  Worlds  October  i,  1902. 
GENTSCH’S  “ NEW  GUTTA-PERCHA.” 
The  method  of  producing  the  substitute  for  Gutta-percha  referred 
to  at  length  in  The  India  Rubber  World  of  September  i (page  385)  as 
the  “ New  Gutta-percha”  is  the  invention  of  Adolf  Gextsch,  of 
\'ienna,  and  covered  by  patents,  granted  first  in  Austria-Hungary, 
and  later  in  Germany  and  elsewhere.  The  German  patent  is 
No.  1 16,092  (date  of  application  June  24,  1S99),  the  specification 
for  which  states  that  the  method  consists  of  the  mixing  of  India- 
rubber  with  vegetable  wax.  after  which  thickened  oil  may  be  added. 
The  mixture  is  kneaded  in  a slowly  rising  temperature,  which  may 
be  done  to  advantage  in  a kneading  machine,  care  being  taken  not 
to  bring  the  temperature  so  high  as  to  melt  the  wax.  A fixed 
proportion  of  ingredients  cannot  be  prescribed.  Waxes  having  a 
high  melting  point  are  used  alone  or  mixed  with  thickened  oil,  as 
