Having had occasion to prepare a quantity of sulphurous anhydride, for
the purpose of reducing chromates previous to their analysis, I made use
of the following apparatus, as represented in the accompanying figure.
It consists of a glass vessel, A, provided with three tubulars,
otherwise resembling a large Wolff bottle, the large tube, B, being
provided with a stopper for the purpose of introducing pieces of sulphur
from time to time into the small dish, C, intended for its reception,
and fed with air by means of the delivery tube, D, thus allowing the
stream of gas caused by the consumption of the sulphur to escape by
means of the exit tube, E, to the vessel desired to receive it.
[Illustration]
In using the apparatus the sulphur is first kindled by introducing a red
hot wire through the tube, B, and replacing the stopper that has been
momentarily removed for the introduction of the same. A slight blast is
now maintained from the bellows that are in connection with the pipe, D,
until the whole of the sulphur is thoroughly kindled, when a somewhat
more powerful blast may be applied. When the apparatus above described
is in full working order, from 2 to 3 lb. of sodium carbonate may be
converted into sodium sulphite in less than half an hour, or several
gallons of water saturated. I have also on connecting the apparatus with
a powerful refrigerator obtained in a short time a large quantity of
liquid SO2. It will be found advantageous, however, during the
preparation of sulphurous anhydride, to employ a layer of water covering
the bottom of the vessel to about 1 inch in depth. Carbonic anhydride
and phosphoric anhydride may also be readily obtained in any desired
quantity by slight alteration; but in case of phosphorus the air must be
allowed to enter only gently, since a rapid current would at all times
determine the fracture of the vessel.--_Chem. News_.
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