C 2 24 ] 



>ter, about as much as inflammable air is idimi° 

 nifhed in the fame circumftances. For this pur- 

 pofe I kept for fo me months a quart bottle full of 

 each of thefe kinds of air ; but as different quanti- 

 ties of inflammable air vary very much in this re- 

 flect, it. is not improbable but that nitrous air may 

 vary alfo. 



From one trial that I made, I conclude that ni- 

 trous air may be kept in a bladder much better than 

 moft other kinds of air. The air to which I refer 

 was kept about a fortnight in a bladder, through 

 which the peculiar fmell of the nitrous air was 

 •very fenfible for feveral days. In a day or two the 

 ibladder became red, and was much contracted in 

 its dimenfions. The air within it had loft very 

 little of its peculiar property of diminiming com- 

 mon air. 



I did not endeavour to afcertain the exact quan- 

 tity of nitrous air produced from given quantities 

 of all the metals which yield it ; but the few ob- 

 fervations which 1 did make for this purpofe I mail 

 recite in this place : 



dwt. gr. 



6 o of filver yielded tyl ounce meafu res 



5 19 of quickfilver 4f 



1 2| of copper 14! 



2 o of brafs 21 



20 of iron 16 



1 5 of bifmuth 6 



o 12 of nickel 4 



VII. Of 



