vol/lxix.] philosophical transactions. 531 



tions, or gave a loose to imagination, because I was rather prejudiced against the 

 inflammable air, after I had seen various animals immediately die in it, and I 

 was rather tearful when I first began to breathe it : besides, this facility of breath- 

 ing it, accompanied with a pleasing sensation, I have constantly observed in all 

 my experiments on this subject. 



This pleasure however I paid very dear for in another experiment, in which I 

 was near losing my life. Having filled a bladder of the largest sort with about 

 350 cubic inches of inflammable air, extracted from iron filings through water, 

 which air was not at all diminished by the mixture of nitrous air ; I began to 

 breathe it boldly, owing to the encouragement received from the above related 

 experiment, and resolved to breathe it as long as my strength would permit me, 

 after having made a very violent expiration in order to evacuate the lungs of the 

 atmospheric air. Having made the first inspiration I felt a great oppression on 

 my lungs. Towards the middle of the 2d inspiration I heard Mr. Cavallo, who 

 favoured me with his assistance in these experiments, say, that I was become 

 very pale : by this time the objects appeared confused to my eyes. Notwith- 

 standing this, I made the 3d inspiration ; but now my strength failing, I lost 

 my sight entirely, and fell on my knees. In this situation I breathed the air of 

 the room, but my knees not being able to support me, I fell entirely on the 

 floor. However, in a short time I came to myself, so as to be able to get up, 

 &c. ; but my respiration continued to be aftected with difticulty and pain, as if 

 I had a great weight on the breast ; nor did I perfectly recover till the next day. 

 It must be observed, that during this experiment I kept my nose close stopped. 



This same inflammable air contained in the bladder, which I had breathed 3 

 times, was examined in various manners, and was found to be as inflammable as 

 before ; it exploded as usual, when mixed with dephlogisticated air ; but after 

 having been shaken in water for a short time, being tried with the nitrous air, 

 it gave III — 10, IV— 10, whereas before it was not at all diminished. At 

 this time the common air, with the same nitrous air, gave II — 14, II -f- lo. 

 Hence it appears that the inflammable air, after being breathed, is rather better 

 than before, because in that case it is a little diminished by the addition of ni- 

 trous air. 



In order to ascertain whether this alteration was occasioned by the bladder, I 

 made the following experiment, which, having been often repeated, was con- 

 stantly attended with the same event. I introduced into a bladder, which was 

 sometimes moist and sometimes dry, a quantity of inflammable air, extracted as 

 well from zinc as from iron, through water, and having kept it in that situation 

 for some minutes, beating in the mean while the bladder, to keep the air in agi- 

 tation, I afterwards took it out, and by the mixture of nitrous air observed, that 

 it suffered no diminution, exactly as it suftered none before it had been put into 



3 Y 2 



