23^ 7)r. Priestley’s Objervations on 
and confequently unelaftic, fulphureous, laline, and other 
floating particles, will mod: ealily coaiefce, whereby they 
are rendered too grofs to enter the minute vellcles, w'hich 
are alfo much contracted, as well by the lofs of the elafti- 
city of the confined air, as by the contraction occasioned by 
the itimulating acid fulphureous vapours. And hence it 
is not improbable, that one great defign of nature in the 
ftruCture of this important and wonderful vifcus , was to 
frame the veficles lo very minute, thereby effectually to 
hinder the ingrefs of grofs, feculent particles, which 
might be injurious to the animal economy. 
Daftly, lie concludes, that the effeCt of refpiration is to 
abate, and in part delfroy, the elafticity of the air; and as 
this was effected by fuphureous vapours, and he could 
breathe for a longer time air that had palled through 
cloaths dipped in a folution of fait of tartar, he con- 
cluded, that the air had been mended by the tartar hav- 
ing ftrongly imbibed the fulphureous, acid, and watery 
vapours, vol. I. p. 267. 
hauler, after reciting the opinions of all that had 
gone before him, fuppofes, with Dr. hales, that, in con- 
fequence of the air lofing its fpring in the lungs, they 
cannot be kept dilated; and therefore, they muft collapfe, 
and the circulation of the blood be impeded, vol. III. p. 
258. When he dates his opinion concerning the ufe of 
the lungs more fully, he fays, that the true ufe of 
them is partly inhaling, and partly exhaling, p. 351. 
That the lungs inhale both water and air; but that in the 
lungs the air lofes its elaflic property, fo as to be ealily 
foluble in water or vapour, p. 352.: and he thinks it 
probable, 
