428  artificial  formation  of  glycerine. 
1st.  In  powder. 
Pulverised  lactate  of  zinc    .    .    1  to  16  grammes. 
Pulverised  sugar  of  milk     .    .    5  " 
Forming  20  doses — three  each  day. 
2nd.  In  pills. 
Pulverised  lactate  of  zinc     .    .    1  to  16  grammes. 
Syrup  of  gum  q.  s. 
For  20  to  40  pills—- three  to  six  each  day. 
Chemist,  June  1857,  from  Journ.  de  Pharm.  et  de  Chimie. 
ON  THE  ARTIFICIAL  FORMATION  OF  GLYCERINE. 
By  A.  Wurtz. 
In  a  note  on  acetal  and  the  glycols,  the  author  put  forward 
the  opinion,  that  the  processes  adapted  to  cause  the  synthesis  of 
the  glycols,  or  diatomic  alcohols,  ought  also  to  lead  to  the  forma- 
tion of  the  glycerines  or  triatomic  alcohols.  A  glycerine  is,  in 
fact,  derived  from  a  bromide  of  carbonated  hydrogen,  Cn  Hn_  ^r3, 
by  the  substitution  of  an  equivalent  of  oxygen  and  an  equivalent 
of  water  for  each  equivalent  of  bromine  : — 
O  Hnf-1Brs=  O  H*+206+3HBr. 
These  bromides  may  be  prepared  in  various  ways,  and  by 
taking  advantage  of  the  powerful  affinity  of  bromide  for  silver, 
the  above  substitution  may  be  effected. 
The  compound  C6  H5  Br3  may  be  prepared  in  three  ways. 
One  of  these  consists  in  treating  iodide  of  allyle,  C6  H5 1,  or 
iodized  propylene  of  Berthelot,  with  bromine.  The  iodized  liquid 
is  placed  in  a  long-necked  flask,  surrounded  by  a  refrigerating 
mixture,  and  one  and  a  half  times  its  weight  of  bromine  is  added 
in  small  quantities.  The  iodine  separates  in  a  crystalline  form, 
whilst  3  equivs.  of  bromine  are  fixed  upon  the  group  C6  H5. 
The  tribromide  thus  obtained,  when  properly  purified,  forms 
a  dense  colorless  liquid,  which  is  slightly  rose-colored  if  it  re- 
tains a  trace  of  iodine.  At  a  temperature  below  50°  F.  it  crys- 
tallizes in  fine  colorless  prisms,  which  fuse  at  61°  F.  It  distils 
unaltered  at  422°-423°  F.  205  grms.  of  acetate  of  silver  were 
treated  with  115  grms.  of  this  tribromide,  dissolved  in  5  or  6 
times  its  volume  of  crystallizable  acetic  acid.    The  paste  thus 
