Chemtjlfy. 89 



ift, Becaufe nitrous air can never be obtained of the fame 

 degree of ftrength. 



adiy, When one meafure of nitrous air is added to one 

 meafure of atmofpheric air, the abforption will be great or 

 fmall, according to the time the air remains over the water, 

 or is agitated in it. 



Having made feven trials with this inftrument, with the 

 fame atmofpheric air, I obtained a diminution, at the firft 

 experiment, of, 



o 60 



2d, o <fi 



3d, o 95 



4th, o 87 



5th, o 90 



6th, o 93 



7th, o 100 



From this it is evident that Dr, Davidfoh was deceived 

 in fuppofing that the air of Martinique was much Durer than 

 the air of Europe, and that the error lay in his inftrument. 

 The nitrous air which I ufed was procured from nitric acid 

 diluted with water and copper. 



8. OJ the Bafe of the Muriatic Acid. 



Mr. William Lambe, in an eflay in the fifth volume of 

 the Manchefter Memoirs, has attempted to prove that ful- 

 phurated hydrogen is the bafe of the muriatic acid. He ob- 

 tained ox. muriatic gas by dropping fulphuric acid upon the 

 refiduum left after evaporating water which had been im- 

 pregnated with hepatic gas in which iron and mar.ganefej 

 had been digefted. I have performed this experiment, and 

 the refult is exactly as ftated by Mr. Lambe. 



Two drachms of the filings of bar-iron were placed in 

 twenty-two ounce meafures of diftilled water, which had 

 been impregnated with fulphurated hydrogen gas in Nooth's 

 ajiparatus. In five days twelve ounce meafures of inflam- 

 mable air efcapcd from the water. Six ounces of the clear 

 fluid evaporated to drynefs, left a rcfiduum, confifting of de- 

 phlogifticated muriat of iroji, which attra61;ed the moifture of 



Vol. VII. N th« 



