[ 2 44 ] 



may hold the phlogifton too fait, to be deprived of it 

 by this acid vapour. 



I (hall conclude my account of thefe experiments 

 with obferving, that the electric fpark is vifible in 

 the vapour of fpirit of fait, exactly as it is in common 

 air ; and though I kept making this fpark a conii- 

 derable time in a quantity of it, I did not perceive 

 that any fenfible alteration was made in it. A little 

 inflammable air was produced, but not more than 

 might have come from the two iron nails which I 

 made ufe of in taking the fparks. 



X. 



Miscellaneous Observations. 



Many of the preceding obfervations relating to* 

 the vinous and putrefactive fermentations, I- had 

 the curiofity to endeavour to afcertain in what 

 manner the air would be affected by the acetous 

 fermentation. For this purpofe I inclofed a phiak 

 full of fmall beer in a jar {landing in water, and 

 obferved that during the firft two or three days 

 there was an increafe of the air in the jar* but 

 from that time it gradually decreafed, till at length 

 there appeared to be a diminution of about ._!g. of 

 the whole quantity. During this time the whole 

 fur face of it was gradually covered with a..fcum, 

 beautifully corrugated. After this there was an: 

 increafe of the air till there was- more than the 

 original quantity ; but this mult have been fixed: 

 air, not incorporated with the reft of the mafs ; for r , 

 withdrawing the beer, which I found to be four, 

 after it had flood i&or 20 days under the jar, and- 



palling 



