NATURE OF THE BLEACHING COMPOUNDS OF CHLORINE. 281 



It attacks the epidermis with great activity. A drop left in contact 

 with the skin for half a minute destroys it, and more deeply than nitric 

 acid does in the same space of time. The tint which it acquires is red- 

 dish brown, and not yellow. 



Chlorous acid when slightly concentrated is extremely unstable, and 

 decomposes partially even at common temperatures. During the great 

 heat of summer it can only be preserved for a few days, except by 

 keeping it in ice. When more diluted and kept from the light it may, 

 on the contrary, be preserved for a much longer time. During this 

 decomposition it disengages an infinite number of small bubbles, which 

 are merely chlorine gas, and at the same time a certain quantity of 

 chloric acid is formed. Agitation, especially with angular bodies, 

 hastens this decomposition ; and when fragments of powdered glass 

 are thrown into this acid, their contact with the liquor is followed by 

 a well-marked effervescence. 



At a moderately high temperature, the decomposition is much more 

 rapid. Yet it is only partial at 212°, for chlorous acid may be distilled 

 at the usual pressure, and thus brought to a higher degree of concen- 

 tration. 



A sti'ong light produces similar decomposition. A few moments 

 exposure to the solar rays are sufficient to convert it into chlorine and 

 chloric acid. Sometimes also deutoxide of chlorine is formed. 



When an aqueous solution of chlorous acid is exposed to the influ- 

 ence of the voltaic pile, an abundant disengagement of oxygen takes 

 place at the positive pole. The portion of the liquid in the midst of 

 \\ hich this disengagement is effected, does not appear to change its 

 nature by absorbing a certain quantity of the gas. It does not deepen 

 in colour, nor does its decolorizing property appear to diminish. Thus 

 the action even of nascent oxygen does not seem to have the power of 

 changing chlorous acid into chloric acid or deutoxide of chlorine. 



In this experiment no chlorine is disengaged at the positive pole. 

 There is no doubt that chlorous acid and water are simultaneously de- 

 composed, and that the hydrogen and chlorine, meeting in the nascent 

 ptate, form hydrochloric acid. What tends to induce this opinion is, 

 that at the end of a certain time the oxygen obtained is mixed with 

 chlorine; aphaenomenon which could not occur, except there be formed 

 in the liquid a compound in which this body is electro-negative. 



Chlorine cannot exert any action on the aqueous solution of chlorous 

 acid ; but it is different with bromine and iodine. Each of these bodies 

 is susceptible of decomposing it, and of acidification at the expense of 

 its oxygen. 



If a few drops of bromine be put in contact with a small quantity of 

 chlorous acid, a disengagement of chlorine is perceived on the surface 

 of the drops of bromine. On exposing this liquid to the contact of the 

 air for a few seconds, this latter compniuid is liberated, and free bromic 



