1 6 8 Analyfn of the Ah. 



Then, before I took them out of the water, 

 I kt the bolthead and lower part of the cylin- 

 drical glafs a y into the earthen veffel x x, 

 full of water ; and having lifted all out of 

 the great veffel of water, I marked the fur- 

 face z of the water in the glafs ay. 



If the ingredients in the bolthead, upon 

 fermenting, generated Air, then the water 

 would fall from z toy, and the empty fpace 

 zy was equal to the bulk of the quantity 

 of Air generated : But if the ingredients, 

 upon fermentation, did abforb or fix the 

 active particles of Air, then the furface of 

 the water would afcend from z to n> and 

 the fpace z n, which was filled with water, 

 was equal to the bulk of Air, which was 

 abforbed by the ingredients, or by the fume 

 arifing from them: When the quantities of 

 Air, either generated or abforbed, were very 

 great, then I made nfe of large chymical re- 

 ceivers inftead of the glafs a y: But if thefe 

 quantities were very fmall, then, inftead of 

 the bolthead, and deep cylindrical glafs a y x 

 I made ufe of a fmall cylindrical glafs, or 

 a common beer glafs inverted, and placed 

 under it a phial or jelly-glafs, taking care that 

 the water did not come at the ingredients 

 ]n them;,, which was eafily prevented by 



drawing 



