ON IODINE AND BROMINE. 
235 
property which this possesses of displacing bromine from its 
combinations. It, moreover, permits a useful application of 
the mother waters of iodine, which hitherto were valueless. 
The mother waters of barilla, after the iodine has been pre- 
cipitated by chlorine as has been described, contain bromine 
in the state of a metallic bromide, when care is taken not to 
add more chlorine than is rigorously required to precipitate 
all the iodine. There are added, to one thousand two hundred 
and fifty parts of these mother waters, thirty-two parts of 
peroxide of manganese in powder, and twenty-four of sul- 
phuric acid at 66°. The whole is poured into a tubulated 
glass retort to which is adapted a tubulated globe receiver, 
and to this last a tube which communicates with a proof glass. 
The retort and globe, as also the globe and the tube, should be so 
exactly fitted to each other as to admit of its adaption with- 
out lute or stuffing, which would inevitably be destroyed by 
the action of the chlorine. All being thus arranged, the 
retort is heated, so as to cause the liquid to boil; the bromine 
condenses in the globe under the form of red oily striae with 
a small quantity of water; the operation is interrupted when 
red vapour ceases to come over. 
By gently heating the globe without displacing the appa- 
ratus, the bromine is driven over into the proof glass, where 
upon cooling it will be condensed. 
The mother waters which have been employed in this 
preparation, are to be rejected, when it is ascertained that they 
contain no more bromine by the addition of a new quantity 
of sulphuric acid and oxide of manganese. 
Journal de Pharmacie, 
