AmxZZ'im&im'}      Production  of  the  Alkaline  Metals.  543 
these  are  made  small  in  diameter,  which  partially  removes  this  great 
disadvantage  of  the  method,  the  expensive  cylinders  are  rapidly  ren- 
dered worthless  from  the  effects  of  the  intense  heat. 
In  doing  away  with  the  use  of  lime  and  an  excess  of  carbon,  the 
main  causes  which  have  hitherto  prevented  a  full  yield  of  metal  are 
removed,  and  thus,  with  the  aid  of  other  advantages  described,  I  am 
enabled  to  obtain  fully  ninety  per  cent,  of  metal  instead  of  thirty  per 
cent.,  as  formerly.  By  the  old  process  lime  must  be  added  to  prevent 
fusion,  to  insure  any  reduction;  yet,  at  the  same  time  it  forms,  with  a 
portion  of  the  soda,  the  compound  known  as  soda-lime,  and  from  this 
substance  carbon  reduces  sodium  only  at  the  most  intense  heat.  In 
practice,  according  to  the  old  method,  four  pounds  of  carbon  are 
used  to  every  nine  pounds  of  sodium  carbonate.  This  is  twice  the 
amount  theoretically  required  to  reduce  all  the  sodium,  even  assuming 
the  gas  resulting  from  the  reduction  to  be  wholly  carbonic-oxide. 
When,  however,  but  one-third  the  total  amount  of  sodium  is  all  that 
is  obtained  from  a  charge,  the  proportion  between  the  sodium  pro- 
duced and  carbon  used  becomes  as  one  is  to  six.  The  effect  of  an 
excess  of  carbon  in  the  mixture,  which,  as  previously  explained,  is 
really  necessary,  is  to  produce  an  excessive  amount  of  carbonic-oxide, 
and  this,  together  with  the  excess  of  carbon,  combines  with  the 
metallic  vapors  of  sodium,  forming  various  compounds,  from,  which 
the  metal  cannot  be  distilled.  By  reducing  caustic-soda  with  the 
carbide  of  a  metal,  or  its  equivalent,  and  using  only  sufficient  carbon 
to  carry  out  the  reaction  stated  above,  the  gases  given  off  consist  of 
hydrogen,  carbonic-oxide  and  carbonic-acid,  which  mixture  has  little 
or  no  effect  upon  the  vapors  of  sodium.  The  crucibles,  after  treat- 
ment, contain  a  small  amount  of  carbonate  of  soda  and  all  the  iron 
of  the  "  carbide  "  still  in  a  fine  state  of  division,  together  with  a  very 
small  percentage  of  carbon.  These  residues  in  the  crucibles  are 
treated  with  warm  water,  and  the  solution  of  soda  evaporated  to 
recover  the  carbonate  of  soda,  while  the  fine  iron  is  dried,  mixed 
with  tar  and  coked  to  produce  more  of  the  so-called  "  carbide  equiva- 
lent."   
Boric  Acid  has  been  found  by  Dr.  J.  L.  Minor,  of  Memphis,  Tenn.  (N.  Y. 
Med.  Jour.  July  31,  1886),  to  be  an  efficient  remedy,  though  not  a  specific,  in 
granular  lids.  The  powder  is  applied  to  the  affected  parts  by  means  of  a 
camel's  hair  brush  from  three  times  a  week  to  three  times  a  day,  the  difference 
depending  upon  both  the  individual  and  the  disease. 
