Analyfis of the Air. z 1 1 



Experiment XCIV. 



March 12th, 1 of a cubick inch of filings 

 of Iron, with a cubick inch of compoiaid 

 Aqua-foi'tis, and an equal quantity of water, 

 for the firft half hour abforbed five or fix 

 cubick inches of air; but in an hour more 

 it had emitted that quantity of air; and in 

 two hours more it again reforbed what had 

 been juft before emitred. The day following 

 it continued abibrbing, in all 12 cubick in- 

 ches: And then remained flationary for 15 

 or 20 hours. The third day it had again re- 

 mitted or generated three or four cubick 

 inches of air, and thence continued flationary 

 for five or fix days. 



It is remarkable, that the fame mixtures 

 fhould change from generating to abibrbing, 

 and from abibrbing to generating flates 5 fome- 

 times with, and ibmetimes without any fen- 

 lible alteration of the temperature of the air. 

 See Vol. II. p. 237 , 293. 



A like quantity of filings pf Iron, and oil 

 of Vitriol y made no fenfible ferment, and 

 generated a very little air ; but upon pouring 

 in an equal quantity of water, it generated 

 in 21 days 43 cubick inches of air; and in 3 

 or 4 days more it reforbed 3 cubick inches of 



air ; 



