282 BALARD'S RESEARCHES CONCERNING THE 
acid remains. This is a process which might be successfully adopted 
for preparing bromic acid, if others easier of execution did not exist. 
’ Iodine acts in the same manner, but, as might be anticipated, its 
action is more energetic ; when the chlorous acid is concentrated it is 
accompanied with a slight disengagement of heat. Chlorine is abun- 
dantly evolved, and a portion of iodine is acidified, whilst another 
small portion is changed into chloride of iodine. 
The acid formed under these circumstances, treated by nitrate of 
silver, gives a white and not a yellow precipitate soluble in ammonia, 
and which is merely iodate of silver. The product of this action is 
merely iodic and not hyperiodic acid, as might be suspected according 
to the mode of preparing this acid proposed by MM. Magnus and Am- 
mermuller, to whom the discovery of it is owing. 
Among the simple non-metallic combustibles, azote and hydrogen 
in the gaseous state appear to have no action upon chlorous acid; but 
sulphur, selenium, phosphorus and arsenic act upon it with great 
energy. By their contact with this compound they undergo analogous 
alterations ; they are acidified, and give rise to an abundant disengage- 
ment of chlorine gas. The sulphur is converted into sulphuric acid, 
the phosphorus into phosphoric acid, and the arsenic into arsenic acid, 
as happens when they are treated with nitric acid. As to selenium, 
it produces also selenic and not selenious acid; that is to say, the 
chlorous acid performs then what nitric acid itself cannot effect. The 
whole of the chlorine is not disengaged in the state of gas; a small 
portion combines with the elementary body, so that there are produced 
at the same time chloride of phosphorus, of sulphur, of arsenic, &e. ; 
these by the contact of water undergo double decomposition, the pro- 
ducts of which are water and additional portions of phosphoric, sul- 
phuric, and arsenic acids. 
Charcoal in powder did not appear to me to exert any action on 
chlorous acid. As to that of boron and silicium, the want of materials 
has not allowed of my ascertaining it. 
Chlorous acid acts variously with metallic substances; potassium 
thrown in pieces into chlorous acid burns immediately without any 
disengagement of chlorine being perceived. The product of this com- 
bination is formed of chloride of potassium and chlorite of potash. The 
presence of water, which may complicate the action, does not allow of 
accurately determining what passes during its operation. It is, however, 
probable that it is at the expense of the chlorous acid, that these two 
compounds of chlorine are formed, and that the water merely dissolves 
the resulis of this decomposition. 
Tron filings, when made to act upon chlorous acid, decompose it in- 
stantaneously ; the action is accompanied with an abundant emission of 
heat, and a brisk effervescence produced by the chlorine. ‘The iron. is 
oxidized, the chlorine is partly disengaged, and also in part combines 
fe ee 
