4 
Ordinary Meeting, October 19th, 1875. 
Edward Schungk, Ph.D., F.RS., &c., President, in the 
Chair. 
“ On some Reactions of Bromine and Iodine,” by Professor 
C. SCHORLEMMER, F.R.S. 
Although it is well known that iodine dissolves in chlo- 
roform and some other liquids, such as carbon-sulphide and 
petroleum-naphtha, with a line purple and bromine with a 
yellow colour, it seems not to be known that, under certain 
conditions, a colourless solution may be obtained containing 
both these elements in the free state. 
Thus on adding dilute chlorine water drop by drop to a 
weak solution of potassium iodide and bromide, containing 
an excess of the latter, and shaking the liquid at the same 
time with chloroform, the purple colour of the iodine makes 
first its appearance, but gradually becomes fainter and at 
last disappears completely. It is, however, not easy to hit 
exactly the point, when the chloroform becomes quite 
colourless, but this is readily effected by adding so much 
chlorine water that the chloroform assumes a faint yellow 
tint, and then shaking the liquid with a cold and dilute so- 
lution of sodium bicarbonate, which must be carefully added 
drop b}^ drop. It is easily proved that the colourless solu- 
tion thus formed contains both free bromine and iodine, for 
on adding more bicarbonate, in order to remove the free 
bromine, the purple colour gradually appears again. 
I am not able as yet to explain these facts ; it is not a 
case of two complementary colours neutralising each other 
as I first assumed; for on mixing dilute solutions of the two 
elements in dry chloroform no colourless solution can be ob- 
tained. It seems that the presence of water has something 
