phosphoric anhydride

This compound on heating with phosphoric anhydride loses water and yields anthraquinone, It may be prepared in a similar manner by heating phthalyl chloride with benzene in the presence of aluminium chloride.

Of the hygroscopic substances in common use, phosphoric anhydride, concentrated sulphuric acid, and dry potassium hydrate are almost equal in power; sodium hydrate and calcium chloride are not much behind.

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.

Phosphoric anhydride, when heated to low redness, burns with a pale flame in fluorine, forming a gaseous mixture of fluorides and oxyfluoride of phosphorus.

Sulphur 17.07 Manganese 30.31 Phosphoric anhydride 0.61 Iron 7.13 Bases 35.04 An analysis of an average sample gave: Per cent.