BEHAVIOUR OF CHARCOAL WITH CHLORINE, ETC. 243 
ART. LI.-ON THE BEHAVIOUR OF VEGETABLE CHARCOAL 
TOWARDS CHLORINE, IODINE, BR(AhNE, CHLORIDE OF 
LIME AND HYPONITRIC ACID. 
By Pkof. C. F. Schonbein. 
Vegetable charcoal destroys ozone very rapidly. The 
resemblance which ozone bears to chlorine, iodine and bro- 
mine led to the following experiments : — 1. When so much 
chlorine is mixed with atmospheric air that the gaseous mix- 
ture appears yellowish, iiistantly colours iodine of potassium 
paste blackish-blue, and immediately bleaches indigo paper, 
—the chlorine instantly disappears on shaking the gas with 
charcoal powder. 2. When chlorine is passed through a glass 
tube filled with charcoal powder, the charcoal becomes 
heated ; and only when this has extended throughout the 
whole length of the charcoal, does the chlorine make its 
appearance at the other end of the tube. The charcoal thus 
treated does not evolve the odour of chlorine, and when 
exposed to the air, gives off muriatic acid vapours ; when 
treated with water, it does not part with chlorine, but only 
with muriatic acid ; nor does it disengage chlorine when 
heated, but it decomposes iodide of potassium, destroys in- 
digo, and turns tincture of guaiacum blue; this property, how- 
ever, it loses by long exposure to the air. 3. When chlorine 
water is shaken with charcoal powder, it is quickly deprived 
of its colour, odour and bleaching power, and the liquid 
contains muriatic acid. 4. The same is the case with a so- 
lution of the hyperchlorite of lime. 5. The brown liquid 
from peroxide of manganese and muriatic acid is quickly 
decolorized by being shaken with charcoal powder, and de- 
prived of its odour and bleaching power, that is to say, the 
chloride of manganese is reduced to protochloride. 6. The 
most dense atmosphere of bromine vapour is absorbed by 
