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Ihave frequently mentioned my having, at one 

 time, expofed equal quantities of different kinds of 

 air in jars (landing in boiled water. The common 

 air in this experiment was diminished four fevenths, 

 and the remainder extinguished flame. This ex- 

 periment demon fi rates that water does not abforb 

 air equally, but that it decornpofes it, taking one 

 part, and leaving the reft. To be quite fure of 

 this fact, I agitated a quantity of common air in 

 boiled water,, and when I had reduced it from ele- 

 ven ounce meafures to feven, I found that it extin- 

 guished a candle, but a moufe lived in it very well. 

 At another time a candle barely went out when 

 the air was diminifhed one third, and at other 

 times I have found this effecl: take place at other 

 very different degrees of diminution. This dif- 

 ference I attribute to the differences in the ffate of 

 the water with refpecl: to the air contained in it;, 

 for fometimes it had flood longer than at other 

 times before I made ufe. of it. I alfo ufed diflilled 

 water, rainwater, and water out of which the air 

 had been pumped, promifcuouily with rain water. 

 I even doubt not but that, in a certain (late of the 

 water, there might be no fenfible difference in the 

 bulk of the agitated air, and yet at the end of the 

 procels it would extinguish a candle, air-being fup- 

 plied from the water in the place of that part off 

 the common air which had been abforbed.. 



It is certainly a little extraordinary that the very 

 fame procels Should fo far mend putrid air, .as to re- 

 duce it to the frandardof air in which candles have 

 burned out ; andyet that it mould fo far injure com- 

 mon and. wholelome ai.r„ as to reduce it to about 



thee 



