A  ApJriiBi'5  m2RM  }     A  New  Source  of  Potash  Supply.  153 
One  hundred  parts  air- dried  cobs  yield,  after  drying  at  212°  Fah., 
the  following  results  : 
Cobs. 
Ashes. 
KCl.       K2  CO3  . 
Silica,  Charcoal, 
Lime,  Iron. 
Loss. 
1st, 
91-70 
1-120 
•820  -750 
•140 
•230 
2d, 
90-95 
1-040 
•805  -745 
•180 
•115 
3d, 
92-85 
1-015 
•840  -755 
•245 
•005 
4th, 
90-94 
1-115 
•830  .795 
•300 
•020 
Averagiii 
g,  91-61 
1-072 
•824  -762 
.217 
•093 
Or,  one  hundred  parts  dried 
suits  : 
at  212°  Fah., 
give  the  following  re- 
Ashes. 
KOI. 
Silica,  Charcoal, 
K2  CO3  .         Lime,  Iron. 
Loss. 
1st, 
1-221 
•894 
•818 
•150 
•253 
2d, 
1-143 
•885 
•819 
•192 
•132 
3d, 
1-093 
•904 
.834 
•252 
•007 
4th, 
1-226 
•913 
•874 
.329 
•030 
An  average  of  1  171 
•899 
•836 
•230 
.105 
The  cobs  were  incinerated  as  thoroughly  as  possible  without  the 
use  of  nitric  acid  or  other  oxidizing  agent,  the  presence  of  silica  im- 
peding the  complete  combustion  of  the  charcoal.  The  ashes  were 
assayed  by  exhausting  them  with  water  and  filtering  off  the  soluble 
portion,  leaving  a  residue  on  the  filter  consisting  of  silica,  charcoal,, 
carbonate  of  lime,  and  a  trace  of  iron.  The  filtrate  was  supersatu- 
rated with  muriatic  acid,  evaporated  to  dryness  and  redissolved  in 
acidulated  water,  leaving  an  additional  quantity  of  silica,  which  was 
added  to  the  first  portion  and  weighed  with  it.  The  solution  was 
then  evaporated  to  dryness  and  weighed  as  chloride  of  potassium,  and 
from  this  weight  the  carbonate  was  calculated. 
In  volume  4th,  Watt's  Dictionary  of  Chemistry,  the  results  of  some 
analyses  by  Hoss  are  given,  from  which  it  appears  that  ash,  oak,  elm 
and  willow,  which  of  our  most  common  forest  wood  are  richest  in  pot- 
ash salts,  yield  respectively  *74,  1*50,  3*90  and  2.85  parts  carbonate 
potash  in  one  thousand  of  wood. 
The  average  yield  of  one  thousand  parts  of  cobs,  as  shown  by  the 
tables  above,  is  7-62  parts  carbonate  potash,  or  nearly  twice  as  much 
as  the  best  specimens  of  wood,  and  from  a  material  which  can  fill  its 
