440 
ON  SILICIUM  AND  TITANIUM. 
Pounds.  Years.  Pounds. 
7^  1843       .       .  .  75,964 
118  1844       .       .  .  88,294 
1,060  1845       ..       .  .  168,109 
1,752  1846       ...  .  232,550 
4,561  1847       .       .  .  296,292 
5,966  1848       ..      .  .  375,585 
7,001  1849       .       .  .  449,757 
23,112  1850       .       .  .  782,670 
27,661  1851       .       .  .  368,109 
66,521  1852       .       .  .  806,254 
90,919           fin  January  .  120,499 
69,116          \  In  February  .  111,331 
Thus,  in  the  year  1853,  the  exportation  would  probably  amount 
to  1,300,000  pounds,  and  the  value  of  this,  since  the  increased 
price  consequent  on  the  failure  of  crops  in  Honduras,  would  be 
£225,000. 
JErlangen,  April,  1855.         Pharm.  Journal,  June,  1855. 
Years. 
1831 
1832 
1833 
1834 
1835 
1836 
1837 
1838 
1839 
1840 
1841 
1842 
ON  SILICIUM  AND  TITANIUM. 
By  H.  Sainte-Claire  Deville. 
Amongst  the  compounds  of  oxygen  with  simple  bodies,  there 
is  a  group  of  substances  whose  analogies  are  incontestable,  and 
which  may  be  characterized  by  a  single  feature  in  their  history. 
These  oxides,  which  are  not  acted  upon  by  chlorine  alone,  become 
converted  into  chlorides  when  in  contact  with  charcoal,  under  the 
influence  of  a  current  of  chlorine  at  a  moderate  temperature. 
Amongst  them  I  shall  mention  those  which  will  be  referred  to  in 
this  note,  namely,  silica,  titanic  acid  and  boracic  acid.  The 
radicals  of  these  generally-diffused  substances  have  not  yet  been 
studied  in  all  their  details,  and  I  now  lay  before  the  Academy 
the  result  of  my  researches  upon  this  subject. 
When  sodium  is  treated  with  chloride  or  fluoride  of  silicium  in 
a  tray  placed  in  a  porcelain  tube  heated  to  redness,  the  last 
traces  of  the  metal  may  be  removed  ;  and  all  that  is  then  neces- 
sary is  to  wash  the  residue,  in  order  to  obtain  silicium  with  all 
the  characters  attributed  to  it  by  Berzelius.  But  if  the  portions 
which  do  not  adhere  to  the  tray  be  selected,  put  into  a  crucible, 
surrounded  and  covered  with  pure  fused  chloride  of  sodium,  and 
heated  to  a  sufficiently  high  temperature  for  the  volatilization  of 
