FUSIBILITY  AND  VOLATILITY  OF  METALS.  423 
poses  that  the  liquid  to  be  distilled  is  a  sufficiently  good  conduc- 
tor of  electricity,  and  if  this  is  not  the  case  necessitates  the  in- 
troduction of  such  substances  as  shall  cause  the  liquid  to  become 
a  conductor.  This  circumstance,  therefore,  limits  very  consider- 
ably the  use  of  this  otherwise  efficient  arrangement,  and  it  is  on 
this  account  that  I  venture  to  bring  under  notice  some  other 
*  means  which  I  have  tested  in  a  variety  of  cases,  and  which  inva- 
riably proved  satisfactory. 
In  cases  where  the  introduction  of  any  foreign  matter  into  the 
liquid  about  to  be  distilled  is  undesirable,  I  introduce  through 
the  cork  in  the  tubular  of  the  retort  a  glass  tube,  which  is  drawn 
out  to  a  long  capillary  tube  and  pressed  tightly  to  the  bottom  of 
the  retort.  The  upper  end  of  the  glass  tube  is  connected,  by 
means  of  an  india-rubber  tube,  with  a  generator  of  carbonic  acid, 
or  hydrogen,  or  a  gas-holder  containing  air,  and  whilst  the  distil- 
lation is  going  on  one  of  these  gases  is  passed  in  a  slow  but  con- 
tinuous current  through  the  liquid.  Under  these  conditions,  all 
bumping  is  avoided,  and  the  distillation  proceeds  with  the  utmost 
facility. 
For  ordinary  purposes,  however,  I  have  found  it  still  more 
convenient  to  introduce  into  the  liquid  about  to  be  distilled  a 
small  fragment  of  sodium  amalgam  or,  in  cases  where  the  liquid 
is  acid,  a  small  piece  of  sodium  tin.  Methylic  alcohol  is  well 
known  to  be  one  of  the  most  difficult  liquids  to  distil,  yet,  on  the 
introduction  of  a  minute  piece  of  sodium  amalgam  or  sodium  tin, 
it  can  be  distilled  without  the  slightest  inconvenience.  I  found 
on  one  occasion  that  more  than  400  grammes  of  methylic  alcohol 
distilled  over  with  perfect  steadiness,  and  without  exhausting  the 
activity  of  a  fragment  of  sodium  tin,  weighing  not  more  than 
0-060  grms. 
It  is,  perhaps,  hardly  necessary  to  mention  that  the  action  of 
sodium  amalgam  and  sodium  tin  is  due  to  a  minute  but  continu- 
ous disengagement  of  hydrogen  taking  place  during  the  process 
of  distillation. — Chem.  News^  Lond.  July  30,  1869. 
FUSIBILITY  AND  VOLATILITY  OF  METALS. 
While  engaged  with  experiments  on  the  intrinsic  composition 
