212 Experiments on the Production of Air 



mon in this country (Bavaria), and which, I believe, 

 grows in England. I recollected that, examining it some 

 time, before, with a different view (that of seeing if it 

 might not be made use of with advantage as a substitute 

 for eider-down), and endeavouring to render it very dry 

 by exposing it in a china plate over a chafing-dish of hot 

 embers, when it had acquired a certain degree of heat, 

 small parcels of it quitted the plate of their own accord, 

 and mounted up to the top of the room. 



This convinced me at the time, not only of its ex- 

 treme fineness, but also of the strong attraction which 

 subsists between it and the particles of air ; and it now 

 occurred to me that these qualities not only render it 

 peculiarly proper as a substitute for eider-down, for con- 

 fining heat, but likewise are properties of all others the 

 most necessary to its supplying the place of silk in the 

 production of air, by exposing it in water to the action 

 of the sun's rays. I, therefore, lost no time in making 

 the following experiments. 



Experiment No. 16. 



The large globe (contents, 296 cubic, inches) being 

 filled with fresh spring-water, and 120 grains of poplar- 

 cotton, upon the evening of the 9th of June, and being 

 the next day, the loth of June, exposed to the sun 

 about four hours, upon the morning of the nth the air 

 'produced was removed, and its quantity was found to be 

 if cubic inch. Its quality was very bad, viz. i a -f- i n 

 = 1.65, or 35 degrees only better than thoroughly 

 phlogisticated air (azote). 



Upon the nth, i2th, and ijth, i cubic inch of air 

 only was produced, and this appeared to be as bad as 

 possible ; for, proved with nitrous air, it gave i a -J- i n 

 2, or o. 



