CADMIUM. 
149 
metals.  Our  ordinary  works  on  chemistry  treat  of  the  metal 
very  briefly,  as  of  little  importance — one  of  the  latest  says,  it 
^'has  no  practical  value  in  the  arts  :" — but  if  duly  investigated 
it  will  be  found,  I  think,  to  possess  qualities  highly  useful  to  the 
arts  as  well  as  interesting  to  science. 
The  melting  point  of  cadmium  is  variously  stated  by  authors. 
Some  place  it  indefinitely,  "below  a  red  heat."  Overman  in  his 
Treatise  on  Metallurgy,  marks  it  at  550°  Fahr.,  and  indicates 
600^  as  the  temperature  at  which  the  metal  volatilizes.  Brande, 
Diet.  Science  and  Art,  says  "  it  fuses  and  volatilizes  at  a  temper- 
ature a  little  below  that  at  which  tin  melts."  Webster,  Manual 
of  Chemistry,  states  that  ''it  melts  and  volatilizes  by  a  heat  not 
much  greater  than  that  required  to  vaporize  mercury."  Most 
of  our  chemical  text-books  put  its  melting  point  at  442^^  (from 
Stromeyer).  While  the  New  American  Cyclopaedia,  now  in 
course  of  publication,  places  it,  on  the  authority  of  Daniell,  at 
360^  Fahr. 
It  would  be  interesting  to  determine  this  accurately.  But 
the  heat  being;  too  high  for  measurement  by  the  mercurial  ther- 
mometer, and  having  no  other,  I  have  only  been  able  to  judge 
approximately  by  comparative  tests.  Melted  under  similar  con- 
ditions with  other  metals,  I  find  the  metal  requires  for  its  fusion 
nearly  the  same  heat  as  lead.  It  is  somewhat  later  in  melting, 
but  on  the  other  hand  it  appears  to  congeal  a  little  the  sooner, 
(which  may  be  due  to  a  difference  in  the  conducting  power  of 
the  two  metals.)  I  should,  therefore,  place  its  melting  point  in 
round  numbers  at  600°  Fahr.,  that  of  lead  being  placed  by  dif- 
ferent authors,  at  594°,  600°,  and  612°.  It  volatilizes  at  a  some- 
what higher  temperature,  giving  off  orange-colored  suffocating 
fumes,  which,  when  inhaled  too  freely  leave  a  disagreeable, 
sweetish,  styptic  sensation  upon  the  lips^  and  an  intolerable  and 
persistent  brassy  taste  in  the  mouth  and  fauces,  with  constriction 
of  the  throat,  heaviness  in  the  head,  and  nausea. 
Of  the  general  properties  of  cadmium  as  an  ingredient  in  al- 
loys, Overman,  who  I  believe  is  high  authority  in  metallurgy, 
and  who,  although  too  broad  in  some  of  his  conclusions,  is  more 
rigidly  exact  in  respect  to  the  individual  instances  adduced  than 
others  that  I  have  had  the  opportunity  of  examining,  saj^s : 
"  Cadmium  is  very  soft  and  malleable  and  still  all  its  alloys 
