BEGINNINGS OF MODERN CHEMISTRY 



die burned in this air with a remarkably vigorous 

 flame, very much like that enlarged flame with which 

 a candle burns in nitrous oxide, exposed to iron or liver 

 of sulphur ; but as I had got nothing like this remark- 

 able appearance from any kind of air besides this 

 particular modification of vitrous air, and I knew no 

 vitrous acid was used in the preparation of mercurius 

 calcinatus, I was utterly at a loss to account for 

 it." 4 



The " new air'* was, of course, oxygen. Priestley at 

 once proceeded to examine it by a long series of careful 

 experiments, in which, as will be seen, he discovered 

 most of the remarkable qualities of this gas. Contin- 

 uing his description of these experiments, he says: 



"The flame of the candle, besides being larger, 

 burned with more splendor and heat than in that species 

 of nitrous air ; and a piece of red-hot wood sparkled 

 in it, exactly like paper dipped in a solution of nitre, 

 and it consumed very fast ; an experiment that I had 

 never thought of trying with dephlogisticated nitrous 

 air. 



"... I had so little suspicion of the air from the 

 mercurius calcinatus, etc., being wholesome, that I had 

 not even thought of applying it to the test of nitrous 

 air; but thinking (as my reader must imagine I fre- 

 quently must have done) on the candle burning in it 

 after long agitation in water, it occurred to me at last 

 to make the experiment; and, putting one measure of 

 nitrous air to two measures of this air, I found not only 

 that it was diminished, but that it was diminished 

 quite as much as common air, and that the redness of 



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