Fixed air thrown into the intestines, by way of glyster, has been found to give relief in some cases of putrid disease. _Of Hepatic Air._ Another species of air absorbed by water, but not instantly, is termed _hepatic air_, being produced by the solution of liver of sulphur, or of sulphurated iron, in vitriolic or marine acid. Water imbibes about twice its bulk of this kind of air, and it is then the same thing with the sulphureous waters of Harrowgate. _Of Phosphoric Air._ Phosphoric air is produced by the solution of phosphorus in caustic fixed alkali. If this air be confined by mercury, it will take fire on being admitted to atmospheric, and much more to dephlogisticated air. After agitation in water it loses this property, and the residuum is merely inflammable air, with no great diminution of its bulk. This kind of air, therefore, probably consists of phosphorus dissolved in inflammable air; though it cannot be made by melting it in inflammable air. LECTURE VIII. _Of Dephlogisticated Marine Acid Air._ This species of air is produced by heating spirit of salt with manganese; or more readily, by pouring acid of vitriol on a mixture of salt and manganese, in the proportion of about 16 of the former to 6 of the latter. In this case the acid of vitriol decomposes the salt, and the marine acid, disengaged in the form of air, takes dephlogisticated air from the manganese; so that this species of air seems to consist of marine acid vapour, and dephlogisticated air. This species of air has a peculiarly pungent smell, and is absorbed by water as readily as fixed air. The water takes about twice its bulk of it; and thereby acquires a yellowish tinge. Both this air, and the water impregnated with it, discharges vegetable colours from linen or cotton, and is thereby useful in bleaching. This air when cold coagulates into a yellowish substance. It dissolves mercury, and with it forms _corrosive sublimate_. _Of Phlogisticated Marine Acid Air._ Besides the preceding kinds of air which are slowly absorbed by water, there are others which are absorbed by it very rapidly, so that they cannot be confined but by mercury. Of this kind is _phlogisticated marine acid air_, procured by the acid of vitriol and common salt; the former seizing upon the alkaline basis of the latter, and thereby expelling the marine acid in the form of air. It is called _phlogisticated_ to distinguish it from _dephlogisticated marine acid air_, which seems to be the same thing, with the addition of dephlogisticated air.