ON  CHEMISTRY  APPLIED  TO  THE  ARTS.  255 
greater  part  of  the  chlorine  is  disengaged  without  applying  heat. 
The  residue  treated  with  water  and  the  solution  by  milk  of 
lime,  gives  a  mixture  of  oxide  of  chrome  and  lime,  which  is 
available  for  the  chrome  manufacturers. 
ON  CHEMISTRY  APPLIED  TO  THE  ARTS. 
By  Dr.  F.  Crace  Calvert,  F.R.S.,  F.C.S. 
Bones. — Composition  of  raw  and  boiled  bones.  The  manufacture  of 
superphosphate  of  lime.  Application  to  agriculture.  Bone-black  or 
char,  and  their  use  in  sugar  refining.  Phosphor  as,  its  properties,  extrac- 
tion, and  employment  in  manufacture  of  matches.  Horn  and  ivory,  their 
composition  and  applications. 
Lecture  I. 
I  shall  not  take  up  your  time  by  making  many  preliminary 
remarks,  but  merely  state  that  though  the  heads  of  the  subject 
on  which  I  intend  to  speak  are  not  inviting  ones,  still  we  shall 
find  as  we  progress  that  the  study  of  the  various  matters  which 
I  shall  bring  before  you  is  full  of  interest  and  instruction. 
Further,  it  would  be  difficult  to  name  objects  which  better  illus- 
trate the  ability  of  man  to  turn  to  profitable  account  the  various 
materials  placed  in  his  hands,  or  to  mention  substances  which 
have  received  more  complete  and  skilful  applications  than  those 
we  shall  treat  of  this  evening. 
Bones. — The  composition  of  "green  bones,"  or  bones  in  their 
natural  state,  may  bo  considered  under  two  general  heads,  viz.  : 
— the  animal  matters,  consisting  of  a  substance  called  osseine 
and  a  few  blood-vessels,  and  the  mineral  matters,  chiefly  repre- 
sented by  phosphate  of  lime  and  a  few  other  mineral  salts.  The 
composition  of  bones  has  been  examined  by  many  eminent  chem- 
ists, but  the  most  complete  researches  are  those,  published  in 
1855,  by  M.  Fremy,  who  examined  bones,  not  only  from  various 
classes  of  vertebrated  animals,  but  also  from  different  parts  of 
the  same  animal ;  and  to  enable  you  to  appreciate  some  of  his 
conclusions,  allow  me  to  draw  your  attention  to  the  following 
table :— * 
*  Annates  de  Chimie  et  Physique,  volume  43,  pages  79,  83,  84. 
