424 
FUSIBILITY  AND  VOLATILITY  OF  METALS. 
and  constitution  of  various  pieces  of  silver  money,  made  at  the 
Royal  Netherlands  Mint,  at  Utrecht,  Dr.  A.  von  Riemsdyk 
carried  on  some  experiments  on  the  fusibility  and  volatility  of 
metals,  from  the  published  record  of  -which  we  abstract  the  follow- 
ing :  The  metals  tin,  bismuth,  cadmium,  lead,  and  zinc,  as  chemi- 
cally pure  as  they  can  be  obtained,  were  molten,  in  order  to  pre- 
vent their  oxidation,  in  a  feeble,  but  constant,  current  of  pure 
and  dry  hydrogen  gas.  The  author  found  that — (1)  the  melting 
of  these  metals  does  not,  either  mechanically  or  by  evaporation, 
give  rise  to  any  loss  at  all ;  (2)  that  tin,  lead,  and  bismuth,  when 
kept  in  a  liquid  state,  are  not  volatile  at  temperatures  greatly  in 
excess  of  their  melting  points,  and  that,  at  a  bright  red  heat, 
qnantities  of  2-3433  grms.  of  bismuth,  and  4-5183  grms.  of  lead, 
did  not  lose,  by  being  kept  at  that  temperature  for  one  hour, 
more  than  1  and  0*5  m.m.,  respectively,  by  evaporation,  while 
tin  did  not  exhibit  any  volatility  at  all ;  (3)  that  cadmium  and 
zinc,  though  completely  fixed,  non-volatile,  at  their  melting 
point,  begin  perceptibly  to  volatilise  at  a  few  degrees  above  that 
point  ;  (4)  that  there  does  not  exist  any  relation  at  all  between 
the  fusibility  and  volatility  of  these  metals,  which  may  be 
arranged  in  the  following  manner,  beginning  from  the  most  fusi- 
ble and  most  readily  volatile  : 
Fusibility.  Volatility. 
Tin,  .  .    228-5°  C.  Cadmium. 
Bismuth,    .  .    268-3°  "  Zinc. 
Cadmium,  .  .    320-0°  "  Bismuth. 
Lead,        .  .    326-0°  "  Lead. 
Zinc,         .  .    420-0°  "  Tin. 
(5)  that  the  so-called  Rose's  fusible  metal,  an  alloy  of  tin,  lead 
and  bismuth,  the  melting  point  of  which  is  about  97*5°,  and  cer- 
tainly not  higher,  is  not  perceptibly  volatile  when  heated  to  a 
bright  red  heat  in  a  current  of  pure  hydrogen  gas.  Silver,  un- 
alloyed, melts  at  1040°  C,  pure  gold  at  1240°  C,  while  the 
author  found  that  chemically-pure  copper  requires  a  temperature 
of  1330°  C.  to  become  liquid.  Neither  pure  silver,  nor  pure 
copper,  nor  also  the  alloy  of  silver  and  copper  containing  945- 
lOOOths  of  the  former  metal  (this  alloy  is  the  standard  alloy  of 
the  Netherlands  silver  coins),  loses  anything  at  all  by  volatilisa- 
