Analyfis of the Air. 1 67 



was wanting, upon weighing this vefiel again, 

 was equal to the bulk of the new generjred 

 Air. I chofe to meafure the quantities of Air, 

 and the matter from whence it arofe, by 

 one common meafure of cubick inches, 

 eftimated from the fpecifick gravities of the 

 feveral fubftances, that thereby the propor- 

 tion of one to the other might the more 

 readily be {ten. 



I made ufe of the following means to 

 meafure the great quantities of Air, which 

 were either raifed and generated, or ab- 

 forbed by the fermentation arifing from the 

 mixture of variety of folid and fluid fub- 

 flances, whereby I could eafily eftimate the 

 furprizing efTecls of fermentation on the 

 Air; viz. 



I put into the bolthead b (Fig. 34.) the 

 ingredients, and then run the long neck of 

 the bolthead into the deep cylindrical glafs 

 ay, and inclined the inverted glafs a y, and 

 bolthead, almoft horizontally in a large vef- 

 felj of water, that the water might run into 

 the glafs ay; when it was almoft up to a 

 the top of the bolthead, I then immerfed 

 the bottom of the bolthead, and lower part 

 y or the cylindrical glafs under water, rail- 

 ing at the fame time the end a uppermoft. 



M 4 Then, 



