HENRY CAVENDISH 103 



curious ; but it did not succeed with me ; for though the vessel I used 

 held more than Mr. Warltire's, namely, 24,000 grains of water, and 

 though the experiment was repeated several times with different pro- 

 portions of common and inflammable air, I could never perceive a 

 loss of weight of more than one-fifth of a grain, and commonly none 

 at all. It must be observed, however, that though there were some 

 of the experiments in which it seemed to diminish a little in weight, 

 there were none in which it increased. 



In all the experiments, the inside of the glass globe became dewy, 

 as observed by Mr. Warltire ; but not the least sooty matter could be 

 perceived. Care was taken in all of them to find how much the air 

 was diminished by the explosion, and to observe its test. The result 

 is as follows, the bulk of the inflammable air being expressed in 

 decimals of the common air : 



In these experiments the inflammable air was procured from zinc, 

 as it was in all my experiments, except where otherwise expressed: 

 bujt I made two more experiments, to try whether there was any 

 difference between the air from zinc and that from iron, the quantity 

 of inflammable air being the same in both, namely, 0.331 of the 

 common; but I could not find any difference to be depended on be- 

 tween the two kinds of air, either in the diminution which they suf- 

 fered by the explosion, or the test of the burnt air. 



From the fourth experiment it appears, that 423 measures of 

 inflammable air are nearly sufficient to phlogisticate completely 1000 

 of common air; and that the bulk of the remaining air after the 

 explosion is then very little more than four-fifths of the common air 

 employed ; so that as common air cannot be reduced to a much less 

 bulk than that by any method of phlogistication, we may safely con- 



