VOL. LV.J PHILOSOPHICAL TRANSACTIONS. t4S 



it, through the water, by the same way that it had been conveyed in, and did 

 not seem to have received any harm by this confinement, and by passing through 

 the water; as after 24 hours, by the help of proper food, it was found as lively 

 and active as it was before it had been thus treated. 



A small bird, viz. a green wagtail, being treated in the same manner, conti- 

 nued for an hour in the receiver in the same quantity of fresh air. It breathed 

 f of that time with great ease, but, towards the end of the hour, quicker, and 

 with some struggle. Soon after it was taken out, it grew lively, and again 

 breathed with the same freedom as before the experiment. Our countryman 

 Mayow asserts, that -^ part of the air, in which these small animals are con- 

 fined, is consumed by them before they expire. His experiments merit to be 

 further verified. The experiments here related, which differ in several respects 

 from those of Dr. Mayow, seemed necessary, in order to show that these small 

 animals can live commodiously, for a considerable time, closely confined in the 

 above-mentioned quantity of pure air; and that they suffer no harm in passing 

 into and out of the receiver. 



Dr. B. here remarks that by filling phials with dry sand, instead of water, here 

 used, and emptying them in the Grotto di Cani, or other deadly caverns, those 

 mephitic exhalations (of which so many of the ancients, as well as the moderns, 

 have so much and so variously written) may be collected, and conveyed to a 

 great distance ; and, when duly examined, w ill, doubtless, be found true, per- 

 manent, mineral air, of that kind known to our miners by the name of choak 

 damp. Of which sort the air of the mineral water of Spa appears also to be,' 

 from the following exjx;riment. 



Exper. 5. He took the air which, 1 days before, he had extracted from the 

 Pouhon water, as related in exper. 3. This air he emptied out of the phial into 

 the receiver fixed in the cistern, in the manner described in the foregoing experi- 

 ment. Into the same receiver he also emptied a bladder of air, extracted from 

 the Pouhon water 4 days before. Which 2 parcels of mineral air filled as much 

 of the receiver as had before been filled with common air, in the last-mentioned 

 experiment. Into this mineral air, thus included in the receiver, the mouse 

 was conveyed, which had been employed on the preceding day in the foregoing 

 experiment. On passing into this air, it immediately held up its head very high, 

 and turned it on every side; and in 4 or 5 seconds, without any difficulty of 

 breathing, or other struggle, fell down on one side, and remained without mo- 

 tion. Half a minute after, it was taken out of the receiver, and placed on a 

 table before a window in the open air, where it lay four hours without showing 

 any sign of life, being quite stiff .-md dead. Two other lively mice were suc- 

 cessively treated in the same manner. The appearances in these were exactly 

 the same as in the first. Both of them, after they had been in the mephitic air 



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