44-8 INFLAMMABLE SUBSTANCES. Se&. 33c?.- SECT. 230. (Additional.) Hepatic Air. Tills air fee ms to confiil of fulphur, held iif folution, in vitriolic or marine air. It is in flammable, when mixed with three quarters of its bulk of common air. Nitre will take up' about half the bulk of this air : and when fatu- rated with it, will turn filver black; but if flrong dephlogifticated nitrous acid be dropped into this water, the fuphur will be precipi tated [a]. One entertained, by chymifts, of their phlogifton ; and is confirnied by the fa£t, of its being naturally found' in thofe fpfings from whence iflues petrol, vvhofe exhalations are very inflamable. The refiduum, which remains in the atrriofphere after the corobudion of inflammable air, is extremely noxious to animals. Doffor Pfiefttey takes it to be a combination of phlogijton with pure air, arid, oft this account, calls it phlogijiicated air. But Mr. Lavoifier,. on the contrary, thinks this to be a pri mitive jubjiance of an unchangeable nature, and gives it the Angular name of atmofpberic mephitis. The Editor. [a] The great Swedilh Chemlft Mr. Scheele, was the firft who difcovered the exiftence of this kind of air; and al though his Treatife on Air and Hre has been publifhcd fince the year 1777, hardly any other jihilofopher has carefully examined its Angular properties. Mr. Kirwan has, however, applied himfelf of late to this object ; and has communi cated to the Royal Society, his various and interefting obfer- vations upon it; as thefe were made on veffels over quickfllver, we may depend on the refults, be-aufe, if the veflels are over- water, this air is in great part abforbed by it; and for this circumftance
