Analyfis of the Air . 17 % 
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 5 but in 
the cafe of the damps of mines they are by 
no means to be depended on, becaufe they 
are not a fufficient fereen from fo very 
noxious vapours. 
Experiment CXVIL 
We have from the following Experiment 
a good hint, to make thefe Salts of fervice 
to us in fome other refpeds, &c, 
I fet a lighted Candle under a large re- 
ceiver (Fig. 35.) which contained about 
4 gallons, it continued burning for 3 -]- \ 
minutes, in which time it had abforbed about 
a quart of air. I then filled the receiver 
with frefh air, by pouring it full of water, 
and then emptying of it j when having wiped 
it dry, I lined all the infide with a piece of 
flannel dipped in a lixivium of Sal Tartar y 
and then dryed 5 the flannel was extended 
with little hoops made of pliant twigs. The 
Candle continued burning under the recei- 
T ver 
