BLEACHING COMPOUNDS OF CHLORINE. 
297 
gas was no longer absorbed, I obtained a neutral, bleaching 
liquid, from which no salt was deposited, and which contain- 
ed such a quantity of chlorite, that a few drops of it into 
which was poured a drop of sulphuric acid, evolved so much 
chlorous acid gas, as to produce a powerful explosion by its 
decomposition. There exist both neutral and alkaline chlorites. 
When we pass chlorous acid gas into an alkaline solution, it is 
at first absorbed without colouring the liquid, which retains 
its alkalinity, and from which, though very concentrated, no 
chlorate is deposited. This alkaline chlorite does not bleach 
without the intervention of acids which evolve from it much 
chlorous acid. Its solution may be concentrated in vacuo, or 
by a gentle heat, without being decomposed, and the salt ob- 
tained in a solid state. I have even procured the chlorite of po- 
tassa in the form of delicate lamellar crystals, resembling the 
chlorate, but distinguished from it by the effervescence (due 
to the escape of oxide of chlorine) produced by the action of 
sulphuric acid, diluted with ten times its weight of water; an 
acid which does not decompose the chlorate. The solution of 
this chlorite may be preserved any length of time, if kept 
from the air; in a solid state the salt may be exposed to the 
air without decomposition, provided the atmosphere is not 
sufficiently moist to cause deliquescence, and thence absorp- 
tion of carbonic acid. 
When chlorous acid gas is passed into a solution of alkaline 
chlorite of potassa, or a solution of potassa, until it is no longer 
absorbed, there is a point when the liquid commences to be 
coloured; at that time it loses its alkalinity, and soon deposits 
a large quantity of chlorate of potassa, provided the solution 
be strong and the gas continues to pass into it; but if the so- 
lution be weak, we have a neutral bleaching chlorite without 
formation of chlorate. This neutral solution is capable of ab- 
sorbing an additional quantity of chlorous acid, and becomes 
of a dark yellowish brown colour; but by exposure to the air, 
or to a temperature of 80° Cen., it loses this excess of acid : this 
temperature, if prolonged, decomposes all the chlorite with for- 
mation of chlorate and chloride. 
VOL. II. — NO. iv. 38 
