74 PHILOSOPHICAL TRANSACTIONS. [aNNO 1780. 



the sides of the glass were covered with a whitish scum, which seemed moist, 

 and a diminution took place of more than 1 measure, in 4 hours after, he 

 introduced a second measure of hepatic air, which was followed by a similar 

 diminution and deposit. The next day he added 3 more measures of this last, 

 at the interval of about 4 hours between each ; and still finding a considerable 

 diminution after each, the following day he added another measure; the diminu- 

 tion produced by this last appeared not to exceed 1 measure. He then poured 

 off the residuary air into another jar, and found it not to exceed 3 measures, 

 namely, 5 of vitriolic and 6 of hepatic air, were reduced to 3. kito one mea- 

 sure of this residuary air he introduced a lighted candle: it was immediately 

 quenched. To the 2 remaining measures he added 1 measure of water: by 

 agitation it took up -jV of its bulk. To part the remainder he added nitrous air, 

 which had no effect on it. Another part of it extinguished a candle. It had not 

 a vitriolic smell. 



With nitrous air Mr. K. made the following experiments. First, he found 

 that 2 measures or cubic inches of nitrous and 2 of hepatic air were little altered 

 when first mixed, even by agitation; but after 36 hours both were reduced to 

 rather more than -^ of the whole. Yellow particles of sulphur were deposited 

 both on the mercury, and on the sides of the jar, but the mercury was not 

 blackened. The residuary air had still an hepatic smell, and was somewhat 

 further diminished by water; and in the unabsorbed part a candle burned natu- 

 rally. The water had all the properties of hepatic water. 



On the Action of Hepatic Air, and Acid, Alkaline, and Inflammable Liquids, 

 on each other. — One measure of oil of vitriol, whose specific gravity was 1 .s63, 

 absorbed ^ measures of hepatic air except -^. The acid was whitened by a 

 copious deposition of sulphur. On introducing, over mercury, a measure of 

 red nitrous acid, whose specific gravity was 1.430, to an equal measure of 

 hepatic air; red vapours instantly arose, and only -^ or ^-V of a measure remained 

 in an aerial form ; but as the acid acted on the mercury, he was obliged to carry 

 the jar into the water tub, by which means the whole was absorbed: no sulphur 

 was here precipitated. 



Finding it so difficult to subject hepatic air to the direct action of the con- 

 centrated nitrous acid, he diluted it to that precise degree at which it could not 

 act on mercury without the assistance of heat, and then passed through it an 

 equal bulk of the same hepatic air; the acid was whitened, and -^ of the air 

 absorbed, and the residuum detonated. Repeating the same experiment, with 

 hepatic air from liver of sulphur, he found still more of it absorbed by the acid: 

 but the residuum no longer detonated, but burned with a blue and greenish 

 flame, and sulphur was deposited on the sides of the jar. 



Distilled vinegar absorbs nearly its own bulk of air, and becomes slightly 



