Analyjls of the Air. 275 



occafion to go for a fhort time into an in- 

 fectious air : Which mufflers might, by an 

 eafy contrivance, be fo made as to draw in 

 breath thro' the Diaphragms, and to breathe 

 it out by another vent. 



In thefe and the like cafes this kind of 

 mufflers may be very ferviceable ; but in the 

 cafe of the damps of mines they are by no 

 means to be depended on, becaufe they are 

 not a fufficient fcreen from fo very noxious 

 vapours. 



Experiment CXVII. 



We have from the following Experiment 

 a good hint, to make thefe Salts of fervice to 

 us in fome other refpects, &c. 



I fet a lighted Candle under a large receiver 

 (Fig. 35) which contained about four gal- 

 lons 5 it continued burning for 3 + JL mi- 

 nutes, in which time it had abforbed about 

 a quart of air. I then filled the receiver with 

 frefli air, by pouring it full of water, and 

 then emptying of it ; when having wiped it 

 dry, I lined all the infide with a piece of 

 flannel dipped in a Lixivium of Sal c tartar y 

 and then dried ; the flannel was extended 

 with little hoops made of pliant twigs. The 

 Candle continued burning under the receiver 



T thus 



