PROPERTIES OF PHOSPHOROUS ACID.

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PHOSPHOROUS ACID.

PART LXXXI.

VV HEN phosphorus is burnt slowly, and does not becomecompletely saturated with oxigen, it forms an acid differingfrom the former, called phosphorous acid.

PROPERTIES OF PHOSPHOROUS ACID.

Phosphorous acid is liquid, transparent, and of considerabledensity. It has an unpleasant taste, and emits an alliaceous anddisagreeable odour when rubbed, and especially if warmed.When heated more strongly, part of it is volatilized in the formof a white vapour which is very acute, penetrating, and lumi-nous in the dark. It is much more volatile than phosphoricacid; and always contains a greater or less quantity of phos-phorus.

METHODS OF OBTAINING PHOSPHOROUS ACID.

To obtain phosphorous acid we merely expose phosphorus tothe air: the phosphorus by this means undergoes a slow com-bustion, and is gradually changed into phosphorous acid. To